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DDoS Attack Trends for 2022 Q1

Post Syndicated from Omer Yoachimik original https://blog.cloudflare.com/ddos-attack-trends-for-2022-q1/

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

Welcome to our first DDoS report of 2022, and the ninth in total so far. This report includes new data points and insights both in the application-layer and network-layer sections — as observed across the global Cloudflare network between January and March 2022.

The first quarter of 2022 saw a massive spike in application-layer DDoS attacks, but a decrease in the total number of network-layer DDoS attacks. Despite the decrease, we’ve seen volumetric DDoS attacks surge by up to 645% QoQ, and we mitigated a new zero-day reflection attack with an amplification factor of 220 billion percent.

In the Russian and Ukrainian cyberspace, the most targeted industries were Online Media and Broadcast Media. In our Azerbaijan and Palestinian Cloudflare data centers, we’ve seen enormous spikes in DDoS activity — indicating the presence of botnets operating from within.

The Highlights

The Russian and Ukrainian cyberspace

  • Russian Online Media companies were the most targeted industries within Russia in Q1. The next most targeted was the Internet industry, then Cryptocurrency, and then Retail. While many attacks that targeted Russian Cryptocurrency companies originated in Ukraine or the US, another major source of attacks was from within Russia itself.
  • The majority of HTTP DDoS attacks that targeted Russian companies originated from Germany, the US, Singapore, Finland, India, the Netherlands, and Ukraine. It’s important to note that being able to identify where cyber attack traffic originates is not the same as being able to attribute where the attacker is located.
  • Attacks on Ukraine targeted Broadcast Media and Publishing websites and seem to have been more distributed, originating from more countries — which may indicate the use of global botnets. Still, most of the attack traffic originated from the US, Russia, Germany, China, the UK, and Thailand.

Read more about what Cloudflare is doing to keep the Open Internet flowing into Russia and keep attacks from getting out.

Ransom DDoS attacks

  • In January 2022, over 17% of under-attack respondents reported being targeted by ransom DDoS attacks or receiving a threat in advance.
  • That figure drastically dropped to 6% in February, and then to 3% in March.
  • When compared to previous quarters, we can see that in total, in Q1, only 10% of respondents reported a ransom DDoS attack; a 28% decrease YoY and 52% decrease QoQ.

Application-layer DDoS attacks

  • 2022 Q1 was the busiest quarter in the past 12 months for application-layer attacks. HTTP-layer DDoS attacks increased by 164% YoY and 135% QoQ.
  • Diving deeper into the quarter, in March 2022 there were more HTTP DDoS attacks than in all of Q4 combined (and Q3, and Q1).
  • After four consecutive quarters in a row with China as the top source of HTTP DDoS attacks, the US stepped into the lead this quarter. HTTP DDoS attacks originating from the US increased by a staggering 6,777% QoQ and 2,225% YoY.

Network-layer DDoS attacks

  • Network-layer attacks in Q1 increased by 71% YoY but decreased 58% QoQ.
  • The Telecommunications industry was the most targeted by network-layer DDoS attacks, followed by Gaming and Gambling companies, and the Information Technology and Services industry.
  • Volumetric attacks increased in Q1. Attacks above 10 Mpps (million packets per second) grew by over 300% QoQ, and attacks over 100 Gbps grew by 645% QoQ.

This report is based on DDoS attacks that were automatically detected and mitigated by Cloudflare’s DDoS Protection systems. To learn more about how it works, check out this deep-dive blog post.

A note on how we measure DDoS attacks observed over our network
To analyze attack trends, we calculate the “DDoS activity” rate, which is either the percentage of attack traffic out of the total traffic (attack + clean) observed over our global network, or in a specific location, or in a specific category (e.g., industry or billing country). Measuring the percentages allows us to normalize data points and avoid biases reflected in absolute numbers towards, for example, a Cloudflare data center that receives more total traffic and likely, also more attacks.

To view an interactive version of this report view it on Cloudflare Radar.

Ransom Attacks

Our systems constantly analyze traffic and automatically apply mitigation when DDoS attacks are detected. Each DDoS’d customer is prompted with an automated survey to help us better understand the nature of the attack and the success of the mitigation.

For over two years now, Cloudflare has been surveying attacked customers — one question on the survey being if they received a threat or a ransom note demanding payment in exchange to stop the DDoS attack. In the last quarter, 2021 Q4, we observed a record-breaking level of reported ransom DDoS attacks (one out of every five customers). This quarter, we’ve witnessed a drop in ransom DDoS attacks with only one out of 10 respondents reporting a ransom DDoS attack; a 28% decrease YoY and 52% decrease QoQ.

DDoS Attack Trends for 2022 Q1

When we break it down by month, we can see that January 2022 saw the largest number of respondents reporting receiving a ransom letter in Q1. Almost one out of every five customers (17%).

DDoS Attack Trends for 2022 Q1

Application-layer DDoS attacks

Application-layer DDoS attacks, specifically HTTP DDoS attacks, are attacks that usually aim to disrupt a web server by making it unable to process legitimate user requests. If a server is bombarded with more requests than it can process, the server will drop legitimate requests and — in some cases — crash, resulting in degraded performance or an outage for legitimate users.

DDoS Attack Trends for 2022 Q1

Application-layer DDoS attacks by month

In Q1, application-layer DDoS attacks soared by 164% YoY and 135% QoQ – the busiest quarter within the past year.

Application-layer DDoS attacks increased to new heights in the first quarter of 2022. In March alone, there were more HTTP DDoS attacks than in all of 2021 Q4 combined (and Q3, and Q1).

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

Application-layer DDoS attacks by industry

Consumer Electronics was the most targeted industry in Q1.

Globally, the Consumer Electronics industry was the most attacked with an increase of 5,086% QoQ. Second was the Online Media industry with a 2,131% increase in attacks QoQ. Third were Computer Software companies, with an increase of 76% QoQ and 1,472 YoY.

DDoS Attack Trends for 2022 Q1

However, if we focus only on Ukraine and Russia, we can see that Broadcast Media, Online Media companies, and Internet companies were the most targeted. Read more about what Cloudflare is doing to keep the Open Internet flowing into Russia and keep attacks from getting out.

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

Application-layer DDoS attacks by source country

To understand the origin of the HTTP attacks, we look at the geolocation of the source IP address belonging to the client that generated the attack HTTP requests. Unlike network-layer attacks, source IP addresses cannot be spoofed in HTTP attacks. A high percentage of DDoS activity in a given country usually indicates the presence of botnets operating from within the country’s borders.

After four consecutive quarters in a row with China as the top source of HTTP DDoS attacks, the US stepped into the lead this quarter. HTTP DDoS attacks originating from the US increased by a staggering 6,777% QoQ and 2,225% YoY. Following China in second place are India, Germany, Brazil, and Ukraine.

DDoS Attack Trends for 2022 Q1

Application-layer DDoS attacks by target country

In order to identify which countries are targeted by the most HTTP DDoS attacks, we bucket the DDoS attacks by our customers’ billing countries and represent it as a percentage out of all DDoS attacks.

The US drops to second place, after being first for three consecutive quarters. Organizations in China were targeted the most by HTTP DDoS attacks, followed by the US, Russia, and Cyprus.

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks

While application-layer attacks target the application (Layer 7 of the OSI model) running the service that end users are trying to access (HTTP/S in our case), network-layer attacks aim to overwhelm network infrastructure (such as in-line routers and servers) and the Internet link itself.

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks by month

While HTTP DDoS attacks soared in Q1, network-layer DDoS attacks actually decreased by 58% QoQ, but still increased by 71% YoY.

Diving deeper into Q1, we can see that the amount of network-layer DDoS attacks remained mostly consistent throughout the quarter with about a third of attacks occurring every month.

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

Cloudflare mitigates zero-day amplification DDoS attack

Amongst these network-layer DDoS attacks are also zero-day DDoS attacks that Cloudflare automatically detected and mitigated.

In the beginning of March, Cloudflare researchers helped investigate and expose a zero-day vulnerability in Mitel business phone systems that amongst other possible exploitations, also enables attackers to launch an amplification DDoS attack. This type of attack reflects traffic off vulnerable Mitel servers to victims, amplifying the amount of traffic sent in the process by an amplification factor of 220 billion percent in this specific case. You can read more about it in our recent blog post.

We observed several of these attacks across our network. One of them targeted a North American cloud provider using the Cloudflare Magic Transit service. The attack originated from 100 source IPs mainly from the US, UK, Canada, Netherlands, Australia, and approximately 20 other countries. It peaked above 50 Mpps (~22 Gbps) and was automatically detected and mitigated by Cloudflare systems.

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks by industry

Many network-layer DDoS attacks target Cloudflare’s IP ranges directly. These IP ranges serve our WAF/CDN customers, Cloudflare authoritative DNS, Cloudflare public DNS resolver 1.1.1.1,  Cloudflare Zero Trust products, and our corporate offices, to name a few. Additionally, we also allocate dedicated IP addresses to customers via our Spectrum product and advertise the IP prefixes of other companies via our Magic Transit, Magic WAN, and Magic Firewall Products for L3/4 DDoS protection.

In this report, for the first time, we’ve begun classifying network-layer DDoS attacks according to the industries of our customers using the Spectrum and Magic products. This classification allows us to understand which industries are targeted the most by network-layer DDoS attacks.

When we look at Q1 statistics, we can see that in terms of attack packets and attack bytes launched towards Cloudflare customers, the Telecommunications industry was targeted the most.  More than 8% of all attack bytes and 10% of all attack packets that Cloudflare mitigated targeted Telecommunications companies.

Following not too far behind, in second and third place were the Gaming / Gambling and Information Technology and Services industries.

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks by target country

Similarly to the classification by our customers’ industry, we can also bucket attacks by our customers’ billing country as we do for application-layer DDoS attacks, to identify the top attacked countries.

Looking at Q1 numbers, we can see that the US was targeted by the highest percentage of DDoS attacks traffic — over 10% of all attack packets and almost 8% of all attack bytes. Following the US is China, Canada, and Singapore.

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks by ingress country

When trying to understand where network-layer DDoS attacks originate, we cannot use the same method as we use for the application-layer attack analysis. To launch an application-layer DDoS attack, successful handshakes must occur between the client and the server in order to establish an HTTP/S connection. For a successful handshake to occur, the attacker cannot spoof their source IP address. While the attacker may use botnets, proxies, and other methods to obfuscate their identity, the attacking client’s source IP location does sufficiently represent the attack source of application-layer DDoS attacks.

On the other hand, to launch network-layer DDoS attacks, in most cases, no handshake is needed. Attackers can spoof the source IP address in order to obfuscate the attack source and introduce randomness into the attack properties, which can make it harder for simple DDoS protection systems to block the attack. So if we were to derive the source country based on a spoofed source IP, we would get a ‘spoofed country’.

For this reason, when analyzing network-layer DDoS attack sources, we bucket the traffic by the Cloudflare edge data center locations where the traffic was ingested, and not by the (potentially) spoofed source IP to get an understanding of where the attacks originate from. We are able to achieve geographical accuracy in our report because we have data centers in over 270 cities around the world. However, even this method is not 100% accurate, as traffic may be back hauled and routed via various Internet Service Providers and countries for reasons that vary from cost reduction to congestion and failure management.

In Q1, the percentage of attacks detected in Cloudflare’s data centers in Azerbaijan increased by 16,624% QoQ and 96,900% YoY, making it the country with the highest percentage of network-layer DDoS activity (48.5%).

Following our Azerbaijanian data center is our Palestinian data center where a staggering 41.9% of all traffic was DDoS traffic. This represents a 10,120% increase QoQ and 46,456% YoY.

DDoS Attack Trends for 2022 Q1

DDoS Attack Trends for 2022 Q1

To view all regions and countries, check out the interactive map.

Attack vectors

SYN Floods remain the most popular DDoS attack vector, while use of generic UDP floods drops significantly in Q1.

An attack vector is a term used to describe the method that the attacker uses to launch their DDoS attack, i.e., the IP protocol, packet attributes such as TCP flags, flooding method, and other criteria.

In Q1, SYN floods accounted for 57% of all network-layer DDoS attacks, representing a 69% increase QoQ and a 13% increase YoY. In second place, attacks over SSDP surged by over 1,100% QoQ. Following were RST floods and attacks over UDP. Last quarter, generic UDP floods took the second place, but this time, generic UDP DDoS attacks plummeted by 87% QoQ from 32% to a mere 3.9%.

DDoS Attack Trends for 2022 Q1

Emerging threats

Identifying the top attack vectors helps organizations understand the threat landscape. In turn, this may help them improve their security posture to protect against those threats. Similarly, learning about new emerging threats that may not yet account for a significant portion of attacks, can help mitigate them before they become a significant force.

When we look at new emerging attack vectors in Q1, we can see increases in DDoS attacks reflecting off of Lantronix services (+971% QoQ) and SSDP reflection attacks (+724% QoQ). Additionally, SYN-ACK attacks increased by 437% and attacks by Mirai botnets by 321% QoQ.

Attacker reflecting traffic off of Lantronix Discovery Service

Lantronix is a US-based software and hardware company that provides solutions for Internet of Things (IoT) management amongst their vast offering. One of the tools that they provide to manage their IoT components is the Lantronix Discovery Protocol. It is a command-line tool that helps to search and find Lantronix devices. The discovery tool is UDP-based, meaning that no handshake is required. The source IP can be spoofed. So an attacker can use the tool to search for publicly exposed Lantronix devices using a 4 byte request, which will then in turn respond with a 30 byte response from port 30718. By spoofing the source IP of the victim, all Lantronix devices will target their responses to the victim — resulting in a reflection/amplification attack.

Simple Service Discovery Protocol used for reflection DDoS attacks

The Simple Service Discovery Protocol (SSDP) protocol works similarly to the Lantronix Discovery protocol, but for Universal Plug and Play (UPnP) devices such as network-connected printers. By abusing the SSDP protocol, attackers can generate a reflection-based DDoS attack overwhelming the target’s infrastructure and taking their Internet properties offline. You can read more about SSDP-based DDoS attacks here.

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks by attack rate

In Q1, we observed a massive uptick in volumetric DDoS attacks — both from the packet rate and bitrate perspective. Attacks over 10 Mpps grew by over 300% QoQ, and attacks over 100 Gbps grew by 645% QoQ.

There are different ways of measuring the size of an L3/4 DDoS attack. One is the volume of traffic it delivers, measured as the bit rate (specifically, terabits per second or gigabits per second). Another is the number of packets it delivers, measured as the packet rate (specifically, millions of packets per second).

Attacks with high bit rates attempt to cause a denial-of-service event by clogging the Internet link, while attacks with high packet rates attempt to overwhelm the servers, routers, or other in-line hardware appliances. These devices dedicate a certain amount of memory and computation power to process each packet. Therefore, by bombarding it with many packets, the appliance can be left with no further processing resources. In such a case, packets are “dropped,” i.e., the appliance is unable to process them. For users, this results in service disruptions and denial of service.

Distribution by packet rate

The majority of network-layer DDoS attacks remain below 50,000 packets per second. While 50 kpps is on the lower side of the spectrum at Cloudflare scale, it can still easily take down unprotected Internet properties and congest even a standard Gigabit Ethernet connection.

DDoS Attack Trends for 2022 Q1

When we look at the changes in the attack sizes, we can see that attacks of over 10 Mpps grew by over 300% QoQ. Similarly, attacks of 1-10 Mpps grew by almost 40% QoQ.

DDoS Attack Trends for 2022 Q1

Distribution by bitrate

In Q1, most of the network-layer DDoS attacks remain below 500 Mbps. This too is a tiny drop in the water at Cloudflare scale, but can very quickly shut down unprotected Internet properties with less capacity or at the very least congest, even a standard Gigabit Ethernet connection.

DDoS Attack Trends for 2022 Q1
Graph of the distribution of network-layer DDoS attacks by bit rate in 2022 Q1

Similarly to the trends observed in the packet-per-second realm, here we can also see large increases. The amount of DDoS attacks that peaked over 100 Gbps increased by 645% QoQ; attacks peaking between 10 Gbps to 100 Gbps increased by 407%; attacks peaking between 1 Gbps to 10 Gbps increased by 88%; and even attacks peaking between 500 Mbps to 1 Gbps increased by almost 20% QoQ.

DDoS Attack Trends for 2022 Q1

Network-layer DDoS attacks by duration

Most attacks remain under one hour in duration, reiterating the need for automated always-on DDoS mitigation solutions.

We measure the duration of an attack by recording the difference between when it is first detected by our systems as an attack and the last packet we see with that attack signature towards that specific target.

In previous reports, we provided a breakdown of ‘attacks under an hour’, and larger time ranges. However, in most cases over 90 percent of attacks last less than an hour. So starting from this report, we broke down the short attacks and grouped them by shorter time ranges to provide better granularity.

One important thing to keep in mind is that even if an attack lasts only a few minutes, if it is successful, the repercussions could last well beyond the initial attack duration. IT personnel responding to a successful attack may spend hours and even days restoring their services.

In the first quarter of 2022, more than half of the attacks lasted 10-20 minutes, approximately 40% ended within 10 minutes, another ~5% lasted 20-40 minutes, and the remaining lasted longer than 40 minutes.

DDoS Attack Trends for 2022 Q1

Short attacks can easily go undetected, especially burst attacks that, within seconds, bombard a target with a significant number of packets, bytes, or requests. In this case, DDoS protection services that rely on manual mitigation by security analysis have no chance in mitigating the attack in time. They can only learn from it in their post-attack analysis, then deploy a new rule that filters the attack fingerprint and hope to catch it next time. Similarly, using an “on-demand” service, where the security team will redirect traffic to a DDoS provider during the attack, is also inefficient because the attack will already be over before the traffic routes to the on-demand DDoS provider.

It’s recommended that companies use automated, always-on DDoS protection services that analyze traffic and apply real-time fingerprinting fast enough to block short-lived attacks.

Summary

Cloudflare’s mission is to help build a better Internet. A better Internet is one that is more secure, faster, and reliable for everyone — even in the face of DDoS attacks. As part of our mission, since 2017, we’ve been providing unmetered and unlimited DDoS protection for free to all of our customers. Over the years, it has become increasingly easier for attackers to launch DDoS attacks. But as easy as it has become, we want to make sure that it is even easier — and free — for organizations of all sizes to protect themselves against DDoS attacks of all types.

Not using Cloudflare yet? Start now with our Free and Pro plans to protect your websites, or contact us for comprehensive DDoS protection for your entire network using Magic Transit.

CVE-2022-26143: A Zero-Day vulnerability for launching UDP amplification DDoS attacks

Post Syndicated from Omer Yoachimik original https://blog.cloudflare.com/cve-2022-26143-amplification-attack/

CVE-2022-26143: A Zero-Day vulnerability for launching UDP amplification DDoS attacks

CVE-2022-26143: A Zero-Day vulnerability for launching UDP amplification DDoS attacks

A zero-day vulnerability in the Mitel MiCollab business phone system has recently been discovered (CVE-2022-26143). This vulnerability, called TP240PhoneHome, which Cloudflare customers are already protected against, can be used to launch UDP amplification attacks. This type of attack reflects traffic off vulnerable servers to victims, amplifying the amount of traffic sent in the process by an amplification factor of 220 billion percent in this specific case.

Cloudflare has been actively involved in investigating the TP240PhoneHome exploit, along with other members of the InfoSec community. Read our joint disclosure here for more details. As far as we can tell, the vulnerability has been exploited as early as February 18, 2022. We have deployed emergency mitigation rules to protect Cloudflare customers against the amplification DDoS attacks.

Mitel has been informed of the vulnerability. As of February 22, they have issued a high severity security advisory advising their customers to block exploitation attempts using a firewall, until a software patch is made available. Cloudflare Magic Transit customers can use the Magic Firewall to block external traffic to the exposed Mitel UDP port 10074 by following the example in the screenshot below, or by pasting the following expression into their Magic Firewall rule editor and selecting the Block action:

(udp.dstport eq 10074).

CVE-2022-26143: A Zero-Day vulnerability for launching UDP amplification DDoS attacks
Creating a Magic Firewall rule to block traffic to port 10074

To learn more, register for our webinar on March 23rd, 2022.

Exploiting the vulnerability to launch DDoS attacks

Mitel Networks is based in Canada and provides business communications and collaboration products to over 70 million business users around the world. Amongst their enterprise collaboration products is the aforementioned Mitel MiCollab platform, known to be used in critical infrastructure such as municipal governments, schools, and emergency services. The vulnerability was discovered in the Mitel MiCollab platform.

The vulnerability manifests as an unauthenticated UDP port that is incorrectly exposed to the public Internet. The call control protocol running on this port can be used to, amongst other things, issue the debugging command startblast. This command does not place real telephone calls; rather, it simulates a “blast” of calls in order to test the system. For each test call that is made, two UDP packets are emitted in response to the issuer of the command.

According to the security advisory, the exploit can “allow a malicious actor to gain unauthorized access to sensitive information and services, cause performance degradations or a denial of service condition on the affected system. If exploited with a denial of service attack, the impacted system may cause significant outbound traffic impacting availability of other services.

Since this is an unauthenticated and connectionless UDP-based protocol, you can use spoofing to direct the response traffic toward any IP and port number — and by doing so, reflect and amplify a DDoS attack to the victim.

We’ve mainly focused on the amplification vector because it can be used to hurt the whole Internet, but the phone systems themselves can likely be hurt in other ways with this vulnerability. This UDP call control port offers many other commands. With some work, it’s likely that you could use this UDP port to commit toll fraud, or to simply render the phone system inoperable. We haven’t assessed these other possibilities, because we do not have access to a device that we can safely test with.

The good news

Fortunately, only a few thousand of these devices are improperly exposed to the public Internet, meaning that this vector can “only” achieve several hundred million packets per second total. This volume of traffic can cause major outages if you’re not protected by an always-on automated DDoS protection service, but it’s nothing to be concerned with if you are.

Furthermore, an attacker can’t run multiple commands at the same time. Instead, the server queues up commands and executes them serially. The fact that you can only launch one attack at a time from these devices, mixed with the fact that you can make that attack for many hours, has fascinating implications. If an attacker chooses to start an attack by specifying a very large number of packets, then that box is “burned” – it can’t be used to attack anyone else until the attack completes.

How Cloudflare detects and mitigates DDoS attacks

To defend organizations against DDoS attacks, we built and operate software-defined systems that run autonomously. They automatically detect and mitigate DDoS attacks across our entire network.

Initially, traffic is routed through the Internet via BGP Anycast to the nearest Cloudflare edge data center. Once the traffic reaches our data center, our DDoS systems sample it asynchronously allowing for out-of-path analysis of traffic without introducing latency penalties.

The analysis is done using data streaming algorithms. Packet samples are compared to the fingerprints and multiple real-time signatures are created based on the dynamic masking of various fingerprint attributes. Each time another packet matches one of the signatures, a counter is increased. When the system qualifies an attack, i.e., the activation threshold is reached for a given signature, a mitigation rule is compiled and pushed inline. The mitigation rule includes the real-time signature and the mitigation action, e.g., drop.

CVE-2022-26143: A Zero-Day vulnerability for launching UDP amplification DDoS attacks

You can read more about our autonomous DDoS protection systems and how they work in our joint-disclosure technical blog post.

Helping build a better Internet

Cloudflare’s mission is to help build a better Internet. A better Internet is one that is more secure, faster, and reliable for everyone — even in the face of DDoS attacks and emerging zero-day threats. As part of our mission, since 2017, we’ve been providing unmetered and unlimited DDoS protection for free to all of our customers. Over the years, it has become increasingly easier for attackers to launch DDoS attacks. To counter the attacker’s advantage, we want to make sure that it is also easy and free for organizations of all sizes to protect themselves against DDoS attacks of all types.

Not using Cloudflare yet? Start now.

CVE-2022-26143: TP240PhoneHome reflection/amplification DDoS attack vector

Post Syndicated from Alex Forster original https://blog.cloudflare.com/cve-2022-26143/

CVE-2022-26143: TP240PhoneHome reflection/amplification DDoS attack vector

Beginning in mid-February 2022, security researchers, network operators, and security vendors observed a spike in DDoS attacks sourced from UDP port 10074 targeting broadband access ISPs, financial institutions, logistics companies, and organizations in other vertical markets.

Upon further investigation, it was determined that the devices abused to launch these attacks are MiCollab and MiVoice Business Express collaboration systems produced by Mitel, which incorporate TP-240 VoIP- processing interface cards and supporting software; their primary function is to provide Internet-based site-to-site voice connectivity for PBX systems.

Approximately 2600 of these systems have been incorrectly provisioned so that an unauthenticated system test facility has been inadvertently exposed to the public Internet, allowing attackers to leverage these PBX VoIP gateways as DDoS reflectors/amplifiers.

Mitel is aware that these systems are being abused to facilitate high-pps (packets-per-second) DDoS attacks, and have been actively working with customers to remediate abusable devices with patched software that disables public access to the system test facility.

In this blog, we will further explore the observed activity, explain how the driver has been abused, and share recommended mitigation steps. This research was created cooperatively among a team of researchers from Akamai SIRT, Cloudflare, Lumen Black Lotus Labs, NETSCOUT ASERT, TELUS, Team Cymru, and The Shadowserver Foundation.

DDoS attacks in the wild

While spikes of network traffic associated with the vulnerable service were observed on January 8th and February 7,th 2022, we believe the first actual attacks leveraging the exploit began on February 18th.

Observed attacks were primarily predicated on packets-per-second, or throughput, and appeared to be UDP reflection/amplification attacks sourced from UDP/10074 that were mainly directed towards destination ports UDP/80 and UDP/443. The single largest observed attack of this type preceding this one was approximately 53 Mpps and 23 Gbps. The average packet size for that attack was approximately 60 bytes, with an attack duration of approximately 5 minutes. The amplified attack packets are not fragmented.

This particular attack vector differs from most UDP reflection/amplification attack methodologies in that the exposed system test facility can be abused to launch a sustained DDoS attack of up to 14 hours in duration by means of a single spoofed attack initiation packet, resulting in a record-setting packet amplification ratio of 4,294,967,296:1. A controlled test of this DDoS attack vector yielded more than 400 Mmpps of sustained DDoS attack traffic.

It should be noted that this single-packet attack initiation capability has the effect of precluding network operator traceback of the spoofed attack initiator traffic. This helps mask the attack traffic generation infrastructure, making it less likely that the attack origin can be traced compared with other UDP reflection/amplification DDoS attack vectors.

Abusing the tp240dvr driver

The abused service on affected Mitel systems is called tp240dvr (“TP-240 driver”) and appears to run as a software bridge to facilitate interactions with TDM/VoIP PCI interface cards. The service listens for commands on UDP/10074 and is not meant to be exposed to the Internet, as confirmed by the manufacturer of these devices. It is this exposure to the Internet that ultimately allows it to be abused.

The tp240dvr service exposes an unusual command that is designed to stress-test its clients in order to facilitate debugging and performance testing. This command can be abused to cause the tp240dvr service to send this stress-test to attack victims. The traffic consists of a high rate of short informative status update packets that can potentially overwhelm victims and cause the DDoS scenario.

This command can also be abused by attackers to launch very high-throughput attacks. Attackers can use specially-crafted commands to cause the tp240dvr service to send larger informative status update packets, significantly increasing the amplification ratio.

By extensively testing isolated virtual TP-240-based systems in a lab setting, researchers were able to cause these devices to generate massive amounts of traffic in response to comparatively small request payloads. We will cover this attack scenario in greater technical depth in the following sections.

Calculating the potential attack impact

As previously mentioned, amplification via this abusable test facility differs substantially from how it is accomplished with most other UDP reflection/amplification DDoS vectors. Typically, reflection/amplification attacks require the attacker to continuously transmit malicious payloads to abusable nodes for as long as they wish to attack the victim. In the case of TP-240 reflection/amplification, this continuous transmission is not necessary to launch high-impact DDoS attacks.

Instead, an attacker leveraging TP-240 reflection/amplification can launch a high-impact DDoS attack using a single packet. Examination of the tp240dvr binary reveals that, due to its design, an attacker can theoretically cause the service to emit 2,147,483,647 responses to a single malicious command. Each response generates two packets on the wire, leading to approximately 4,294,967,294 amplified attack packets being directed toward the attack victim.

For each response to a command, the first packet contains a counter that increments with each sent response. As the counter value increments, the size of this first packet will grow from 36 bytes to 45 bytes. The second packet contains diagnostic output from the function, which can be influenced by the attacker. By optimizing each initiator packet to maximize the size of the second packet, every command will result in amplified packets that are up to 1,184 bytes in length.

In theory, a single abusable node generating the upper limit of 4,294,967,294 packets at a rate of 80kpps would result in an attack duration of roughly 14 hours. Over the course of the attack, the “counter” packets alone would generate roughly 95.5GB of amplified attack traffic destined for the targeted network. The maximally-padded “diagnostic output” packets would account for an additional 2.5TB of attack traffic directed towards the target.

This would yield a sustained flood of just under 393mb/sec of attack traffic from a single reflector/amplifier, all resulting from a single spoofed attack initiator packet of only 1,119 bytes in length. This results in a nearly unimaginable amplification ratio of 2,200,288,816:1 — a multiplier of 220 billion percent, triggered by a single packet.

Upper boundaries of attack volume and simultaneity

The tp240dvr service processes commands using a single thread. This means they can only process a single command at a time, and thus can only be used to launch one attack at a time. In the example scenario presented above, during the 14 hours that the abused device would be attacking the target, it cannot be leveraged to attack any other target. This is somewhat unique in the context of DDoS reflection/amplification vectors.

Although this characteristic also causes the tp240dvr service to be unavailable to legitimate users, it is much preferable to having these devices be leveraged in parallel by multiple attackers — and leaving legitimate operators of these systems to wonder why their outbound Internet data capacity is being consumed at much higher rates.

Additionally, it appears these devices are on relatively low-powered hardware, in terms of their traffic-generation capabilities. On an Internet where 100/Gbps links, dozens of CPU cores, and multi-threading capabilities have become commonplace, we can all be thankful this abusable service is not found on top-of-the-line hardware platforms capable of individually generating millions of packets per second, and running with thousands of parallelized threads.

Lastly, it is also good news that of the tens of thousands of these devices, which have been purchased and deployed historically by governments, commercial enterprises, and other organizations worldwide, a relatively small number of them have been configured in a manner that leaves them in this abusable state, and of those, many have been properly secured and taken offline from an attacker’s perspective.

Collateral impact

The collateral impact of TP-240 reflection/amplification attacks is potentially significant for organizations with Internet-exposed Mitel MiCollab and MiVoice Business Express collaboration systems that are abused as DDoS reflectors/amplifiers.

This may include partial or full interruption of voice communications through these systems, as well as additional service disruption due to transit capacity consumption, state-table exhaustion of NATs, and stateful firewalls, etc.

Wholesale filtering of all UDP/10074-sourced traffic by network operators may potentially overblock legitimate Internet traffic, and is therefore contraindicated.

TP-240 reflection/amplification DDoS attacks are sourced from UDP/10074 and destined for the UDP port of the attacker’s choice. This amplified attack traffic can be detected, classified, traced back, and safely mitigated using standard DDoS defense tools and techniques.

Flow telemetry and packet capture via open-source and commercial analysis systems can alert network operators and end customers of TP-240 reflection/amplification attacks.

Network access control lists (ACLs), flowspec, destination-based remotely triggered blackhole (D/RTBH), source-based remotely triggered blackhole (S/RTBH), and intelligent DDoS mitigation systems can be used to mitigate these attacks.

Network operators should perform reconnaissance to identify and facilitate remediation of abusable TP-240 reflectors/amplifiers on their networks and/or the networks of their customers.  Operators of Mitel MiCollab and MiVoice Business Express collaboration systems should proactively contact Mitel in order to receive specific remediation instructions from the vendor.

Organizations with business-critical public-facing Internet properties should ensure that all relevant network infrastructure, architectural, and operational Best Current Practices (BCPs) have been implemented, including situationally specific network access policies that only permit Internet traffic via required IP protocols and ports. Internet access network traffic to/from internal organizational personnel should be isolated from Internet traffic to/from public-facing Internet properties, and served via separate upstream Internet transit links.

DDoS defenses for all public-facing Internet properties and supporting infrastructure should be implemented in a situationally appropriate manner, including periodic testing to ensure that any changes to the organization’s servers/services/applications are incorporated into its DDoS defense plan.

It is imperative that organizations operating mission-critical public-facing Internet properties and/or infrastructure ensure that all servers/services/application/datastores/infrastructure elements are protected against DDoS attack, and are included in periodic, realistic tests of the organization’s DDoS mitigation plan. Critical ancillary supporting services such as authoritative and recursive DNS servers must be included in this plan.

Network operators should implement ingress and egress source address validation in order to prevent attackers from initiating reflection/amplification DDoS attacks.

All potential DDoS attack mitigation measures described in this document MUST be tested and customized in a situationally appropriate manner prior to deployment on production networks.

Mitigating factors

Operators of Internet-exposed TP-240-based Mitel MiCollab and MiVoice Business Express collaboration systems can prevent abuse of their systems to launch DDoS attacks by blocking incoming Internet traffic destined for UDP/10074 via access control lists (ACLs), firewall rules, and other standard network access control policy enforcement mechanisms.

Mitel have provided patched software versions that prevent TP-240-equipped MiCollab and MiVoice Business Express collaboration systems from being abused as DDoS reflectors/amplifiers by preventing exposure of the service to the Internet. Mitel customers should contact the vendor for remediation instructions.

Collateral impact to abusable TP-240 reflectors/amplifiers can alert network operators and/or end-customers to remove affected systems from “demilitarized zone” (DMZ) networks or Internet Data Centers (IDCs), or to disable relevant UDP port-forwarding rules that allow specific UDP/10074 traffic sourced from the public Internet to reach these devices, thereby preventing them from being abused to launch reflection/amplification DDoS attacks.

The amplified attack traffic is not fragmented, so there is no additional attack component consisting of non-initial fragments, as is the case with many other UDP reflection/amplification DDoS vectors.

Implementation of ingress and egress source-address validation (SAV; also known as anti-spoofing) can prevent attackers from launching reflection/amplification DDoS attacks.

Conclusion

Unfortunately, many abusable services that should not be exposed to the public Internet are nevertheless left open for attackers to exploit. This scenario is yet another example of real-world deployments not adhering to vendor guidance. Vendors can prevent this situation by adopting “safe by default” postures on devices before shipping.

Reflection/amplification DDoS attacks would be impossible to launch if all network operators implemented ingress and egress source-address validation (SAV, also known as anti-spoofing).  The ability to spoof the IP address(es) of the intended attack target(s) is required to launch such attacks. Service providers must continue to implement SAV in their own networks, and require that their downstream customers do so.

As is routinely the case with newer DDoS attack vectors, it appears that after an initial period of employment by advanced attackers with access to bespoke DDoS attack infrastructure, TP-240 reflection/amplification has been weaponized and added to the arsenals of so-called “booter/stresser” DDoS-for-hire services, placing it within the reach of the general attacker population.

Collaboration across the operational, research, and vendor communities is central to the continued viability of the Internet. The quick response to and ongoing remediation of this high-impact DDoS attack vector has only been possible as a result of such collaboration. Organizations with a vested interest in the stability and resiliency of the Internet should embrace and support cross-industry cooperative efforts as a core principle.

The combined efforts of the research and mitigation task force demonstrates that successful collaboration across industry peers to quickly remediate threats to availability and resiliency is not only possible, but is also increasingly critical for the continued viability of the global Internet.

Sources

https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-26143/
https://www.mitel.com/en-ca/support/security-advisories/mitel-product-security-advisory-22-0001
https://www.cisa.gov/uscert/ncas/alerts/TA14-017A
https://www.senki.org/ddos-attack-preparation-workbook/
https://www.manrs.org/resources/
https://www.rfc-editor.org/info/bcp38
https://www.rfc-editor.org/info/bcp84
https://datatracker.ietf.org/doc/html/rfc7039

Research and mitigation task force contributors

Researchers from the following organizations have contributed to the findings and recommendations described in this document:

In particular, the Mitigation Task Force would like to cite Mitel for their exemplary cooperation, rapid response, and ongoing participation in remediation efforts. Mitel quickly created and disseminated patched software, worked with their customers and partners to update affected systems, and supplied valuable expertise as the Task Force worked to formulate this document.