Post Syndicated from Adam Barnett original https://blog.rapid7.com/2024/11/12/patch-tuesday-november-2024/

Microsoft is addressing 90 vulnerabilities this November 2024 Patch Tuesday. Microsoft has evidence of in-the-wild exploitation and/or public disclosure for four of the vulnerabilities published today, although as with last month’s batch, it does not evaluate any of these zero-day vulnerabilities as critical severity (yet). Of those four, Microsoft lists two as exploited in the wild, and both of these are now listed on CISA KEV. Microsoft is aware of some level of public disclosure for three. Microsoft is also patching two further critical remote code execution (RCE) vulnerabilities today. Two browser vulnerabilities have already been published separately this month, and are not included in the total.

Active Directory Certificate Service: zero-day EoP aka EKUwu

CVE-2024-49019 describes an elevation of privilege vulnerability in Active Directory Certificate Services. While the vulnerability only affects assets with the Windows Active Directory Certificate Services role, an attacker who successfully exploits this vulnerability could gain domain admin privileges, so that doesn’t offer much comfort. Unsurprisingly, given the potential prize for attackers, Microsoft assesses future exploitation as more likely. Vulnerable PKI environments are those which include published certificates created using a version 1 certificate template with the source of subject name set to “Supplied in the request” and Enroll permissions granted to a broader set of accounts. Microsoft does not obviously provide any means of determining the certificate template version used to create a certificate, although the advisory does offer recommendations for anyone hoping to secure certificate templates.

There is a significant history of research and exploitation of Active Directory Certificate Services, including the widely-discussed Certified Pre-Owned series, and the discovering researchers have now added further to that corpus, tagging CVE-2024-49019 as ESC15. In keeping with another long-standing infosec tradition, the researcher has provided a fun celebrity vulnerability name — in this case, EKUwu, a portmanteau of EKU (Extended Key Usage) and UwU, an emoticon representing a cute face — as part of their detailed and insightful write-up.

MSHTML: zero-day NTLMv2 hash disclosure

Given the CVSSv3 base score of 6.0, one might almost be forgiven for overlooking CVE-2024-43451, which describes an NTLM hash disclosure spoofing vulnerability in the MSHTML platform which powered Internet Explorer. However, public disclosure and in-the-wild exploitation are always worth a look. Although exploitation requires that the user interact with a malicious file, a successful attacker receives the user’s NTLMv2 hash, and can then use that to authenticate as the user.

Microsoft has arguably scored CVE-2024-43451 correctly according to the CVSSv3.1 specification. However, although the Microsoft CVSSv3 vector describes an impact only to confidentiality, if an attacker can authenticate as the user post-exploitation, a further potential for subsequent impact to integrity and availability now exists; if we take that potential indirect effect into account, the CVSSv3 base score would look more like 8.8, which is the sort of number where alarm bells typically start ringing for many defenders. As a further sting in the tail, the advisory FAQ describes the required user interaction as minimal: left click, right click, or even the highly non-specific “performing an action other than opening or executing [the file]”. There’s certainly the potential for a long tail of exploitation here, especially in environments with more relaxed patching cadence.

The complete Windows catalog from Server 2025 and Windows 11 24H2 all the way back to Server 2008 receives patches for CVE-2024-43451. As Rapid7 has previously noted, MSHTML (also known as Trident) is still fully present in Windows — and unpatched assets are thus vulnerable — regardless of whether or not a Windows asset has Internet Explorer 11 disabled.

Exchange: zero-day sender spoofing

It’s been a few months since we’ve seen any security patches for Exchange, but the streak is now broken with a zero-day vulnerability. Mailserver admins should be paying attention to CVE-2024-49040, which is a publicly disclosed spoofing vulnerability. The specific weakness is CWE-451: User Interface (UI) Misrepresentation of Critical Information, which is often associated with phishing attacks, as well as browser vulnerabilities, and can describe a wide range of misdeeds, from visual truncation and UI overlay to homograph abuse. Microsoft does not yet claim knowledge of in-the-wild exploitation.

The advisory for CVE-2024-49040 hints that post-patching actions may be required for remediation of CVE-2024-49040, and links to further information in a separate article titled “Exchange Server non-RFC compliant P2 FROM header detection”. A careful read of the article doesn’t appear to list any mandatory post-patching actions; instead, there is an optional extra mitigation strategy action around Exchange Transport Rules, as well as an encouragingly detailed explanation of the protection offered by today’s patches. The article showcases that an Exchange-connected email client such as Outlook might display a forged sender as if it were legitimate, which we can all agree is not a good outcome. Attackers don’t have to look far to find other vulnerabilities to chain with this one, since today’s sibling zero-day vulnerability CVE-2024-43451 is certainly an option. On the other hand, let’s take a moment to appreciate the Exchange team’s blog title: “You Had Me at EHLO”.

Patches for CVE-2024-49040 are available for Exchange 2019 CU13 and CU14, as well as Exchange 2016 CU23. It’s worth remembering that both Exchange 2016 and 2019 have an extended end date of 2025-10-14, which is now less than a year away; this despite the fact that the successor for 2016 and 2019, which Microsoft is unsubtly branding as Exchange Server Subscription Edition, isn’t due for release until early in 2025 Q3. Many admins would no doubt prefer a longer upgrade window.

The researcher who reported CVE-2024-49040 also discovered a means to impersonate Microsoft corporate email accounts earlier this year, but went public with his findings after Microsoft dismissed his report; it appears that the relationship has been at least somewhat repaired.

Task Scheduler: zero-day EoP (but not SYSTEM)

Windows Task Scheduler facilitates all sorts of useful outcomes, and if you’re a threat actor, it now offers one more: elevation of privilege via CVE-2024-49039. Microsoft is aware of exploitation in the wild. Given the low attack complexity and low privileges requirement, no requirement for user interaction, high impact across the CIA triad, and changed scope, it’s no surprise that the CVSSv3 base score comes out as a relatively zesty 8.8. However, Windows elevation of privilege vulnerabilities are always most exciting for attackers when they lead directly to SYSTEM privileges, but that’s not the case here. The attacker in this scenario starts out in a low-privileged AppContainer sandbox, and exploitation via a malicious app provides medium integrity level privileges, which is the same as a regular non-administrative user on the system. Still, every step forward for a threat actor is a step back for defenders.

.NET: critical RCE

This month brings patches for CVE-2024-43498, a critical RCE in .NET 9.0 with a CVSSv3 base score of 9.8, which is so seldom a harbinger of good news. Exploitation might mean compromise of a desktop application by loading a malicious file, but most concerningly could also describe RCE in the context of a vulnerable .NET webapp via a specially crafted request. Microsoft assesses exploitation as less likely, but there’s nothing on the advisory which obviously supports that assessment, since this is a low-complexity network attack which requires neither privileges nor user interaction. CVE-2024-43498 is surely worthy of immediate patching. It’s also never a bad idea to review other options for protection, especially for internet-exposed services.

Kerberos: critical RCE

The advisory for CVE-2024-43639 describes a critical RCE in Kerberos with a CVSSv3 base score of 9.8, although not in great detail. The FAQ explains that an unauthenticated attacker could use a specially crafted application to leverage a cryptographic protocol vulnerability in Windows Kerberos to perform remote code execution against the target, but without providing much information about the target or the precise context of code execution. The only safe assumption here is that code execution is in a highly-privileged context on a server which handles key authentication tasks. Patch accordingly.

Microsoft lifecycle update

In Microsoft lifecycle news, the most notable change is the arrival of Windows Server 2025 as a General Availability product at the start of November. Microsoft has announced a number of new features in Server 2025, which we will look forward to discussing in more detail in future editions of this blog.

At the other end of the lifecycle continuum, .NET 6.0 receives its final scheduled updates today; as .NET 6.0 is/was a Long Term Support (LTS) version, and .NET 7.0 is already beyond end of life, the only current upgrade path is to .NET 8.0.

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Summary tables

Apps vulnerabilities

Azure vulnerabilities

Browser vulnerabilities

Developer Tools vulnerabilities

ESU Windows vulnerabilities

Mariner System Center vulnerabilities

Microsoft Office vulnerabilities

Open Source Software vulnerabilities

SQL Server vulnerabilities

Server Software vulnerabilities

Windows vulnerabilities

Updates

• 2024-11-12: corrected CVSSv3 base score for CVE-2024-43639.

Post Syndicated from Adam Barnett original https://blog.rapid7.com/2024/10/08/patch-tuesday-october-2024/

Microsoft is addressing 118 vulnerabilities this October 2024 Patch Tuesday. Microsoft has evidence of in-the-wild exploitation and/or public disclosure for five of the vulnerabilities published today, although it does not rate any of these as critical (yet). Of those five, Microsoft lists two as exploited in the wild, and both of these are now listed on CISA KEV. Microsoft is also patching three further critical remote code execution (RCE) vulnerabilities today. Three browser vulnerabilities have already been published separately this month, and are not included in the total.

Somewhat unusually, we’ll take a look at two of the three critical RCEs published today — CVE-2024-43468 and CVE-2024-43582 — before moving on to the arguably somewhat-less- threatening zero-day vulnerabilities patched today.

Microsoft Configuration Manager: pre-auth RCE

Microsoft Configuration Manager receives a patch for the only vulnerability published by Microsoft today with a CVSS base score of 9.8. Although Microsoft doesn’t tag it as either publicly disclosed or exploited-in-the-wild, the advisory for CVE-2024-43468 appears to describe a no-interaction, low complexity, unauthenticated network RCE against Microsoft Configuration Manager. Exploitation is achieved by sending specially-crafted malicious requests, and leads to code execution in the context of the Configuration Manager server or its underlying database. The relevant update is installed within the Configuration Manager console, and requires specific administrator actions that Microsoft describes in detail in a generic series of articles. Further information and several specific required steps are described in KB29166583.

Confusingly, this KB29166583 was first published over a month ago on 2024-09-04, and was then subsequently unpublished and republished on 2024-09-18, all without any mention of CVE-2024-43468, which was published only today and which KB29166583 apparently remediates. Defenders should read the available documentation carefully, and then probably read it again for good measure.

RPD RPC: pre-auth RCE

Any RDP Server critical RCE is worth patching quickly. CVE-2024-43582 is a pre-auth critical RCE in the Remote Desktop Protocol Server. Exploitation requires an attacker to send deliberately-malformed packets to a Windows RPC host, and leads to code execution in the context of the RPC service, although what this means in practice may depend on factors including RPC Interface Restriction configuration on the target asset. One silver lining: attack complexity is high, since the attacker must win a race condition to access memory improperly.

Winlogon: zero-day EoP

Who doesn’t love a good elevation of privilege vulnerability? Weary blue teamers who see the words “publicly disclosed” on a brand-new advisory know the answer. CVE-2024-43583 describes a flaw in Winlogon which gets an attacker all the way to SYSTEM via abuse of a third-party Input Method Editor (IME) during the sign-on process. The supplementary KB5046254 article explains that the 2024-10-08 patches disable non-Microsoft IME during the sign-in process. On that basis, outright removal of third-party IME is a mitigation available to anyone who is not able to apply today’s patches immediately.

Attack surface reduction is always worth considering, and removal of third-party IMEs certainly accomplishes that. Anyone who needs to keep a third-party IME can still do so, but once today’s patches are applied, that third-party IME will be disabled — only in the context of the sign-in process — to prevent exploitation of CVE-2024-43583. Although Microsoft doesn’t quite spell it out, the only reasonable interpretation of the available information is that an asset with no first-party/Microsoft IME installed would remain vulnerable after patching, since otherwise no IME would be available when attempting to sign in. Use of third-party IME is more likely to be a concern in mixed-language or non-English-speaking contexts. The disclosure process around this vulnerability may not have been entirely smooth; back in September, one of the researchers credited with the discovery expressed discontent with MSRC via X-formerly-known-as-Twitter.

Hyper-V: zero-day container escape

CVE-2024-20659 describes a publicly-disclosed security feature bypass in Hyper-V. Microsoft describes exploitation as both less likely and highly complex. An attacker must be both lucky and resourceful, since only UEFI-enabled hypervisors with certain unspecified hardware are vulnerable, and exploitation requires coordination of a number of factors followed by a well-timed reboot. All this after first achieving a foothold on the same network — although in this context, this likely means access to a VM on the target hypervisor, rather than some other location on the same subnet. The prize for successful exploitation is compromise of the hypervisor kernel.

MSHTML: zero-day XSS

CVE-2024-43573 is an exploited-in-the-wild spoofing vulnerability in MSHTML for which Microsoft is also aware of functional public exploit code; the advisory lists CWE-79 as the weakness, which translates to cross-site scripting (XSS). The advisory is sparse on further detail, although Windows Server 2012/2012 R2 admins who typically install Security Only updates should note that Microsoft is encouraging installation of the Monthly Rollups to ensure remediation in this case. The low CVSSv3 base score of 6.5 reflects the requirement for user interaction and the lack of impact to integrity or availability; a reasonable assumption might be that exploitation leads to improper disclosure of sensitive data, but no other direct effect on the target asset.

cURL: zero-day RCE

Microsoft is most famous for its closed source products, but has cautiously softened its stance on open source considerably in the past quarter century or so. Windows has included components of cURL for almost seven years at this point, along with various other open source components; Microsoft does patch these from time to time, although not always as quickly as defenders might like. Today’s patches for CVE-2024-6197, a publicly-disclosed RCE vulnerability in cURL, continue that trend.

The Microsoft advisory for CVE-2024-6197 clarifies that Windows does not ship libcurl, only the curl command line, but that’s still vulnerable and thus in scope for a fix. Exploitation requires that the user connect to a malicious server controlled by the attacker, and code execution is presumably in the context of the user launching the curl CLI tool on the Windows asset. The cURL project advisory for CVE-2024-6197 was originally published on 2024-07-24, and offers further detail from their perspective. Interestingly, the cURL project describes the most likely outcome of exploitation as a crash, and does not specifically mention RCE, although it is careful not to exclude the possibility of unspecified “more serious results,” which could well mean RCE. Microsoft rates this vulnerability as important, which is on track with the CVSS base score of 8.8.

Management Console: zero-day RCE

CVE-2024-43572 rounds out today’s five zero-day vulnerabilities, and describes a low-complexity, no-user-interaction RCE in Microsoft Management Console. Microsoft is aware of both public functional exploit code and in-the-wild exploitation. The vulnerability is exploited when a user downloads and opens a specially-crafted malicious Microsoft Saved Console (MSC) file, so there’s no suggestion here that the Management Console is vulnerable via network attack. Today’s patches prevent untrusted MSC files from being opened, although the advisory does not describe how Windows will know what’s trusted and what isn’t. Microsoft has chosen to map CVE-2024-43572 to CWE-70, which is a very broad category, the use of which is explicitly discouraged by MITRE.

VS Code Arduino extension: cloud critical RCE

A third critical RCE patched today is hopefully less concerning than its siblings. CVE-2024-43488 is in the Visual Studio Code extension for Arduino, and Microsoft notes that the vulnerability documented by this CVE requires no customer action to resolve. A reasonable question is: what does “no action required” really mean here? Within the advisory, Microsoft both claims to have fully mitigated the vulnerability, and also that there is no plan to fix the vulnerability. As confusing as that all sounds, perhaps the most important takeaway here is that Microsoft is now issuing cloud service CVEs in a stated effort to improve transparency. It’s not clear when the vulnerability was first introduced or when it was remediated, but nevertheless the recent expansion into a whole new class of CVEs is a welcome step by Microsoft.

SharePoint: EoP to SYSTEM

A sparse advisory for CVE-2024-43503, which is an elevation of privilege vulnerability which leads to SYSTEM. Advisories for similar vulnerabilities typically describe the specific SharePoint privileges required, but this one does not, so a reasonable assumption might be that the requirement here is simply minimal Site Member privileges.

Microsoft lifecycle update

Today sees the end of support for Windows 11 22H2 for Home, Pro, Pro Education, Pro for Workstations, and SE editions, as well as for Windows 11 21H2 for Education, Enterprise, and Enterprise multi-session editions. Server 2012 and Server 2012 R2 pass into Year 2 of ESU. Windows Embedded POSReady — the POS stands for Point-of-Sale — receives its final ESU updates today, and that might just be the last gasp for Windows 7 as a whole. As well as patching today’s critical RCE CVE-2024-43468, Intune admins still using Configuration Manager 2303 should look to upgrade to a newer version immediately, because support ends (somewhat unusually) on Thursday this week.

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Summary tables

Apps vulnerabilities

Azure vulnerabilities

Browser vulnerabilities

Developer Tools vulnerabilities

ESU Windows vulnerabilities

Mariner Windows vulnerabilities

Microsoft Office vulnerabilities

SQL Server vulnerabilities

System Center vulnerabilities

Windows vulnerabilities

Post Syndicated from Adam Barnett original https://blog.rapid7.com/2024/09/10/patch-tuesday-september-2024/

Microsoft is addressing 79 vulnerabilities this September 2024 Patch Tuesday. Microsoft has evidence of in-the-wild exploitation and/or public disclosure for four of the vulnerabilities published today; at time of writing, all four are listed on CISA KEV. Microsoft is also patching four critical remote code execution (RCE) vulnerabilities today. Unusually, Microsoft has not patched any browser vulnerabilities yet this month.

Servicing Stack: Windows 10 1507 rollback zero-day RCE

At first glance, the most concerning of today’s exploited-in-the-wild vulnerabilities is CVE-2024-43491, which describes a pre-auth RCE vulnerability caused by a regression in the Windows Servicing Stack that has rolled back fixes for a number of previous vulnerabilities affecting optional components.

The CVSSv3.1 base score is 9.8, which is typically not good news. However, things aren’t quite as bad as they seem: the key takeaway here is that only Windows 10, version 1507 (Windows 10 Enterprise 2015 LTSB and Windows 10 IoT Enterprise 2015 LTSB) is affected. Also, Microsoft notes that while at least some of the accidentally unpatched vulnerabilities were known to be exploited, they haven’t seen in-the-wild exploitation of CVE-2024-43491 itself, and the defect was discovered by Microsoft. All in all, while there are certainly more than a few organizations out there still running Windows 10 1507, most admins can breathe a sigh of relief on this one, and then go back to worrying about everything else.

The Servicing Stack regression described by CVE-2024-43491 was introduced in the March 2024 patches. Those nostalgic few still running Windows 10 1507 should note that patches are required for both Servicing Stack and the regular Windows OS patch released today, and must be applied in that order. Microsoft does not specify which vulnerabilities were accidentally unpatched back in March, although there is a significant list of affected optional components at the end of the FAQ, so potentially the set of vulnerabilities in play is quite long. Given time, an enthusiastic data miner could no doubt come up with a list of likely suspects.

Microsoft does also provide a high-level explanation of what went wrong: the build number of the March 2024 security patch for 1507 triggered a latent code defect in the Servicing Stack, and any optional component which was updated during this time was downgraded to the RTM version. This might sound eerily similar to the Windows OS downgrade attacks disclosed at Black Hat USA 2024 last month, but there’s not obviously any substantial connection between the two. It’s quite likely that someone at Microsoft HQ is carefully reviewing other Windows versions for similar version range-based flaws in the Servicing Stack.

Mark-of-the-Web: zero-day “LNK stomping” security feature bypass

The Mark-of-the-Web (MotW) security feature bypass CVE-2024-38217 is not only known to be exploited, but is also publicly disclosed via an extensive write-up which names the technique “LNK stomping” and highlights that exploitation will typically involve explorer.exe overwriting an existing LNK file. The write-up also links to exploit code on GitHub. Beyond that, the discoverer points to VirusTotal samples going back as far as 2018 to make the case that this has been abused for a very long time indeed.

As is generally the case with MotW bypass vulnerabilities, exploitation occurs when a user downloads and opens a specially-crafted malicious file, which could then bypass the SmartScreen Application Reputation security check and/or the legacy Windows Attachment Services security prompt.

Windows Installer: zero-day EoP

Next up in today’s foursome of exploited-in-the-wild vulnerabilities is CVE-2024-38014: an elevation of privilege vulnerability in Windows Installer. The middling CVSSv3.1 base score of 7.8 lines up with Microsoft’s severity assessment of Important rather than Critical. Exploitation grants code execution as SYSTEM, and although the attack vector is local, this might be at least slightly attractive to malware authors, since both attack complexity and privilege requirements are low, and no user interaction is required.

In this case, CWE-269: Improper Privilege Management presumably describes a means of causing the Windows Installer to be over-generous with the privileged access it requires to install software and configure the OS. All current versions of Windows receive a fix, as well as Server 2008, which Microsoft persists in patching from time to time out of the goodness of its heart, even if the end of official support was almost a year ago now.

Microsoft Publisher: zero-day macro policy bypass

It’s been a little while since we talked about Microsoft Publisher, so today’s publication of CVE-2024-38226 — a local security feature bypass for Office macro policy — gives us a chance to do that. The Preview Pane is not involved, and the description of exploit methodology in the FAQ is welcome, but somewhat unusual: an attacker must not only convince a user to download and open a malicious file, but the attacker must also be authenticated on the system itself, although the FAQ does not explain further.

Moving past those vulnerabilities which are known to be exploited or disclosed already, we see three critical RCE vulns: two in SharePoint, and one in the Windows NAT implementation.

SharePoint: two critical RCEs

Network-vector exploitation of SharePoint RCE CVE-2024-38018 requires that an attacker have Site Member permissions already, but since those aren’t exactly the crown jewels, attack complexity is low, and no user interaction is required, Microsoft very reasonably rates this as Critical on its own proprietary severity scale, and expects that exploitation is more likely.

The second SharePoint critical RCE patched this month is CVE-2024-43464, which describes a deserialization of untrusted data leading to code execution in the context of the SharePoint Server via specially-crafted API calls after uploading a malicious file; one mitigating factor is that the attacker must already have Site Owner permissions or better. This all sounds very similar to CVE-2024-30044, which Rapid7 wrote about back in May 2024.

Windows NAT: critical RCE

Rounding out this month’s critical RCE vulnerabilities is CVE-2024-38119, which describes a use after free flaw in the Windows NAT implementation. Attack vector is listed as adjacent, so an attacker would need an existing foothold on the same network as the target asset before winning a race condition, which bumps up the attack complexity to high. Even though this looks to be pre-auth RCE, Microsoft lists exploitation as less likely. For reasons unknown, Server 2012/2012 R2 does not receive a patch, although all newer supported versions of Windows do.

Exchange: nothing, still?

After a busy couple of months back in March and April 2024, it’s been all quiet on the Exchange front for quite some time, and this month extends that curiously lucky streak.

Microsoft lifecycle update

There are no significant changes to Microsoft product lifecycle during September 2024, although  anyone responsible for Azure Database for MySQL – Single Server has until the sunset date of 2024-09-16 to migrate to a supported service to avoid involuntary forced-migration and server unavailability.

As Rapid7 noted last month, Visual Studio for Mac received its last ever patches on 2024-08-31. Also on 2024-08-31, a number of legacy Azure services reached retirement, including Azure Cache for Redis on Cloud Services (Classic).

October will see significant lifecycle changes for Windows 11: release end date for the 21H2 versions of Windows 11 Enterprise and Education, as well as release end date for 22H2 versions for other Windows 11 editions. Fans of legacy software will already know that Server 2012 and 2012 R2 move into year two of the cash-for-updates Extended Security Update program in October.

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Summary tables

Azure vulnerabilities

ESU vulnerabilities

ESU Windows vulnerabilities

ESU Windows Microsoft Office vulnerabilities

Microsoft Dynamics vulnerabilities

Microsoft Office vulnerabilities

SQL Server vulnerabilities

Windows vulnerabilities

Post Syndicated from Adam Barnett original https://blog.rapid7.com/2024/08/13/patch-tuesday-august-2024/

Microsoft is addressing 88 vulnerabilities this August 2024 Patch Tuesday. Microsoft has evidence of in-the-wild exploitation and/or public disclosure for ten of the vulnerabilities published today, which is significantly more than usual. At time of writing, all six of the known-exploited vulnerabilities patched today are listed on CISA KEV. Microsoft is also patching five critical remote code execution (RCE) vulnerabilities today. 11 browser vulnerabilities have already been published separately this month, and are not included in the total.

Patch Tuesday watchers will know that today’s haul of four publicly-disclosed vulnerabilities and six further exploited-in-the-wild vulnerabilities is a much larger batch than usual. We’ll first address those vulnerabilities where public disclosure exists but no patch is available: the noteworthy Windows OS downgrade attacks disclosed at Black Hat last week. We’ll then examine those vulnerabilities published today which Microsoft knows to be exploited in the wild already, and then take a look at the other publicly-disclosed vulnerabilities published this month.

Windows Update: 50% patched zero-day Downdate attack

First things first: what if your patched Windows asset suddenly wasn’t patched, up to and including the hypervisor? That was the question asked and answered in a Black Hat talk by SafeBreach last week. In response, Microsoft has published two vulnerabilities. Microsoft was first notified of these vulnerabilities back in February 2024, and the advisories concede that the Black Hat talk was “appropriately coordinated with Microsoft.”

CVE-2024-38202 describes an elevation of privilege vulnerability in the Windows Update Stack, and exploitation requires that an attacker convinces an administrative user to perform a system restore — unusual, certainly, but social engineers can accomplish many things. Microsoft optimistically assesses exploitation of this vulnerability as less likely. The advisory does not explain how a user with basic privileges can modify the target asset’s System directory, which is required to plant the malicious system restore files, although the SafeBreach write-up does explain the flaw in significant detail. No patch is yet available, although the advisory states that a security update to mitigate this threat is under development. Microsoft provides several recommended actions, which do not mitigate the vulnerability, but can at least provide additional barriers to exploitation and put in place some useful additional visibility of the attack surface and exploitation attempts. One possible outcome of exploitation is that an attacker could modify the integrity and repair utility so that it will no longer detect corruptions in Windows system files.

CVE-2024-21302 is the second half of the downgrade attack pair discovered by SafeBreach. Exploitation allows an attacker with administrator privileges to replace updated Windows system files with older versions and thus reintroduce vulnerabilities to Virtualization-based security (VBS). Patches are available; however, defenders must note that the patch does not automatically remediate assets, but instead delivers an opt-in Microsoft-signed revocation policy, which brings with it the risk of a boot loop if applied and then improperly reverted. Significant guidance is available under KB5042562: Guidance for blocking rollback of Virtualization-based Security (VBS) related security updates.

Windows WinSock: zero-day EoP

Moving on to known-exploited vulnerabilities: the Windows Ancillary Function Driver for WinSock receives a patch for exploited-in-the-wild elevation of privilege vulnerability CVE-2024-38193. Successful exploitation is via a use-after-free memory management bug, and could lead to SYSTEM privileges. The advisory doesn’t provide further clues, but with existing in-the-wild exploitation, low attack complexity, no user interaction involved, and low privileges required, this is one to patch immediately to keep malware at bay.

Windows Power Dependency Coordinator: zero-day EoP

While we’re looking at exploited-in-the-wild, use-after-free vulnerabilities with minimalist advisories: CVE-2024-38107 also leads to SYSTEM privileges via abuse of the Windows Power Dependency Coordinator, which allows Windows computers to wake almost instantly from sleep. Of course, nothing comes for free: this vulnerability requires no user interaction, has low attack complexity, and requires low privileges. Patch all your Windows assets sooner rather than later.

Windows Kernel: zero-day EoP

Still on the topic of exploited-in-the-wild, elevation-to-SYSTEM vulnerabilities: CVE-2024-38106 requires an attacker to win a race condition which falls under CWE-591: Sensitive Data Storage in Improperly Locked Memory. Although the advisory for CVE-2024-38106 does not provide further detail, a reasonable assumption here might be that the vulnerability could be similar to CVE-2023-36403, where exploitation relies on a flaw in the way the Windows kernel handles locking for registry virtualization, which allows Windows to redirect globally-impactful registry read/write operations to per-user locations to support legacy applications which are not UAC-compatible. Curiously, Windows Server 2012 does not receive a patch for CVE-2024-38106, so either the vulnerability was introduced in a later codebase, or Microsoft is hoping that attackers won’t notice.

Windows SmartScreen: zero-day MotW bypass

CVE-2024-38213 describes a Mark of the Web (MotW) security bypass vulnerability in all current Windows products. An attacker who convinces a user to open a malicious file could bypass SmartScreen, which would normally warn the user about files downloaded from the internet, which Windows would otherwise have tagged with MotW. CVE-2024-38213 likely offers less utility to attackers than a broadly-similar SmartScreen bypass published in February 2024, since unlike today’s offering, the advisory for CVE-2024-21351 also described the potential for code injection into SmartScreen itself. The lower CVSSv3 base score for CVE-2024-21351 reflects that difference.

Edge Internet Explorer mode: zero-day EoP

Although Edge RCE vulnerability CVE-2024-38178 is already known to be exploited in the wild, it likely won’t be top of anyone’s list of greatest concerns this month. The advisory clarifies that successful exploitation would require the attacker to not only convince a user to click a malicious link, but also to first prepare the target asset so that it uses Edge in Internet Explorer Mode. IE Mode provides backwards-compatibility functionality so that users can view legacy websites which rely on the fascinating idiosyncrasies of Internet Explorer; such sites are often served by enterprise legacy web applications, which goes a long way to explaining Microsoft’s continued motivation to keep Internet Explorer somewhat alive. If not already enabled on the target asset, the attacker would have to achieve a modification of Edge settings to enable the “Allow sites to be reloaded in Internet Explorer” setting. Subsequent exploitation would involve convincing the user to open an Internet Explorer mode tab within Edge and then opening the malicious URL. Remediation involves patching Windows itself; all current versions of Windows are affected.

Microsoft Project: zero-day RCE

Rounding out this month’s half dozen exploited-in-the-wild vulnerabilities is CVE-2024-38189, which describes RCE in Microsoft Project. Exploitation requires that an attacker convince the user to open a malicious file, and is possible only where the “Block macros from running in Office files from the Internet” policy is disabled — it is enabled by default — and the “VBA Macro Notification Settings” are set to a low enough level.  Happily, the Preview Pane is not an attack vector in this case.

Microsoft Office: zero-day spoofing

Published last week to acknowledge its public disclosure, and patched today for all current versions of Office, CVE-2024-38200 describes a spoofing vulnerability. Exploitation requires that the user click a malicious link. Although the advisory doesn’t describe the impact, the weakness is CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, and the FAQ mentions outgoing NTLM traffic; reading between the lines, it’s highly likely that NTLM hashes are exposed upon successful exploitation.

The advisory suggests mitigating factors which may already apply, or which may prove helpful to improve security posture: adding users to the Protected Users Security Group, which prevents the use of NTLM authentication, and blocking outbound SMB connections to port 445. Both of these mitigation measures may break legacy authentication in some scenarios.

Somewhat unusually, Microsoft claims to have fixed this vulnerability twice, since in addition to today’s patches, an alternative fix was enabled via Feature Flighting on 2024-07-30 for all in-support versions of Office and 365. Microsoft still recommends that customers update to the 2024-08-13 patches to receive the final version of the fix. Somewhat confusingly, the FAQ then goes on to say that the Security Updates table will be revised when the update is publicly available; however, it’s likely that Microsoft will update the FAQ in the near future to clarify that a this was a minor FAQ editing oversight rather than a suggestion that further patches are expected.

Windows Line Printer Daemon: zero-day RCE

Line Printer Daemon (LPD) vulnerabilities are like buses: you wait ages for one, and then two come along in quick succession. Last month’s denial of service vulnerability is now joined by CVE-2024-38199, a publicly-disclosed RCE vulnerability. Exploitation requires that an attacker sends a malicious print task to a shared vulnerable Windows Line Printer Daemon service across the network. Many admins won’t need to worry about this vulnerability, since Microsoft has been encouraging everyone to migrate away from LPD for almost a decade, and it isn’t installed by default on Windows products newer than Server 2012. Still, patches are available for Windows Server 2008 SP2, Server 2022 23H2, and everything in between.

SharePoint & Exchange update

As something of an olive branch for defenders who may now be eyeing their to-do list with concern, Microsoft has not published any SharePoint or Exchange vulnerabilities this month.

Microsoft lifecycle update

All versions of Visual Studio for Mac retire on 2024-08-31 and will no longer receive any further updates — including security patches — after that date. The URL seems to anticipate that some people will have questions: https://learn.microsoft.com/en-us/visualstudio/mac/what-happened-to-vs-for-mac. Microsoft suggests the C# Dev Kit for Visual Studio Code as one possible alternative.

Summary Charts

Summary Tables

Apps vulnerabilities

Azure vulnerabilities

Browser vulnerabilities

Developer Tools vulnerabilities

Mariner Windows ESU vulnerabilities

Microsoft Dynamics vulnerabilities

Microsoft Office vulnerabilities

Windows vulnerabilities

Windows ESU vulnerabilities

Post Syndicated from Greg Wiseman original https://blog.rapid7.com/2024/07/09/patch-tuesday-july-2024/

Microsoft is addressing 139 vulnerabilities this July 2024 Patch Tuesday, which is on the high side in terms of typical CVE counts. They’ve also republished details for 4 CVEs issued by other vendors that affect Microsoft products. Microsoft has evidence of in-the-wild exploitation for 2 of the vulnerabilities published today. At time of writing, none of the vulnerabilities patched today are listed in CISA’s Known Exploited Vulnerabilities catalog, though we can expect CVE-2024-38080 and CVE-2024-38112 to appear there in short order. Microsoft is also patching 5 critical remote code execution (RCE) vulnerabilities today.

Windows Hyper-V: zero-day EoP

CVE-2024-38080 is an elevation of privilege (EoP) vulnerability affecting Microsoft’s Hyper-V virtualization functionality. Successful exploitation will give an attacker SYSTEM-level privileges. Only more recent editions of Windows are affected; Windows 11 since version 21H2 and Windows Server 2022 (including Server Core).

Windows MSHTML Platform: zero-day Spoofing

The other vulnerability seen exploited in the wild this month is CVE-2024-38112, a Spoofing vulnerability affecting Microsoft’s MSHTML browser engine which can be found on all versions of Windows, including Server editions. User interaction is required for exploitation – for example, a threat actor would need to send the victim a malicious file and convince them to open it. Microsoft is characteristically cagey about what exactly can be spoofed here, though they do indicate that the associated Common Weakness Enumeration (CWE) is CWE-668: Exposure of Resource to Wrong Sphere, which is defined as providing unintended actors with inappropriate access to a resource.

SharePoint: critical post-auth RCE

Similar to a vulnerability seen in May, CVE-2024-38023 is a SharePoint vulnerability that could allow an authenticated attacker with Site Owner permissions or higher to upload a specially crafted file to a SharePoint Server, then craft malicious API requests to trigger deserialization of the file’s parameters, thus enabling them to achieve remote code execution in the context of the SharePoint Server. The CVSS base score of 7.2 reflects the requirement of Site Owner privileges or higher to exploit the vulnerability.

Windows Imaging: critical RCE

All supported versions of Windows (and almost certainly unsupported versions as well) are vulnerable to CVE-2024-38060, a flaw in the Windows Imaging Component related to TIFF (Tagged Image File Format) image processing that could allow an attacker to execute arbitrary code on a system. The example scenario Microsoft provides is simply of an authenticated attacker uploading a specially crafted TIFF image to a server in order to exploit this.

Remote Desktop Licensing Service: multiple critical RCEs

Three critical CVEs related to the Windows Remote Desktop Licensing Service were patched this month. CVE-2024-38074, CVE-2024-38076, and CVE-2024-38077. All three of these carry a CVSS 3.1 base score of 9.8 – if you rely on the Remote Desktop licensing service, best get patching immediately. As a mitigation, consider disabling the service entirely until there is an opportunity to apply the update.

SQL Server

Microsoft has patched a host of CVEs affecting SQL Server, all with a CVSS 3.1 base score of 8.8 and allowing RCE. These specifically affect the OLE DB Provider, so not only do SQL Server instances need to be updated, but client code running vulnerable versions of the connection driver will also need to be addressed. For example, an attacker could use social engineering tactics to dupe an authenticated user into attempting to connect to a SQL Server database configured to return malicious data, allowing arbitrary code execution on the client.

Lifecycle update

Also in SQL Server news this month, Microsoft SQL Server 2014 moves past the end of extended support. From this point onward, Microsoft only guarantees to provide SQL Server 2014 security updates to customers who pay for the Extended Security Updates program.

Summary charts

Summary tables

Azure vulnerabilities

Developer Tools vulnerabilities

ESU Windows vulnerabilities

Microsoft Dynamics vulnerabilities

Microsoft Office vulnerabilities

SQL Server vulnerabilities

System Center vulnerabilities

Windows vulnerabilities

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