You may have rested over the December festive period, but cyber criminals were busy, looking to exploit more than 6,200 newly emerged vulnerabilities (aka CVEs—Common Vulnerabilities and Exposures). So now, having rung in 2023, let’s look back at some of the key vulnerability-related stories and events of 2022’s fourth quarter.
Memory Corruption Led the Way
In Q4 2022 memory corruption and privilege escalation were the most common vulnerability types responsible for cyber-threat events, accounting for 21.5% of all events reported by the ReliaQuest Photon Research team. Type confusion CVEs followed closely (15.8%), and remote code execution (RCE), denial of service (DoS), heap-based overflow, and information disclosure with 10.5% each.
With memory-corruption vulnerabilities, a malicious user can modify a program’s memory in a way that wasn’t intended by the program. They can also be used along with other flaws to set the stage for executing code or escalating privilege.
Figure 1: Exploited vulnerabilities by type, Q4 2022
Security professionals tend to focus on mitigating vulnerabilities with the highest CVSS scores. (CVSS stands for the Common Vulnerability Scoring System used to rate a vulnerability’s threat.) But threat actors often chain together a bunch of lower-severity flaws to achieve initial access, elevate privileges, and so on. So, when it comes to vulnerability management, a risk-based approach is sorely needed—and a firm eye trained on the latest trends observed in the wild.
This approach means looking not only at CVSS scores, but the ways threat actors are using vulnerabilities in attacks and what they’re trying to achieve. This is the whole point of vulnerability intelligence, which helps security teams better understand and prioritize the threats they face.
Hot Topic: ProxyNotShell Sparks Chatter
We monitor discussions about vulnerabilities that take place on criminal forums, webpages, paste websites, social media platforms, chat spaces (Telegram and IRC), and code-hosting platforms (GitHub). The most-discussed vulnerabilities over Q4 2022 were those dubbed ProxyNotShell (CVE-2022-41040 and CVE-2022-41082). ProxyNotShell was first disclosed in September 2022 by Microsoft, and the flaws have been actively exploited by cyber criminals ever since. An early abuser was the “LockBit” ransomware gang, which reportedly began to exploit the Microsoft Exchange flaws in October. A ProxyNotShell patch came out in early November, but the exploitation didn’t stop. The ransomware group “Play” discovered ways to bypass ProxyNotShell URL rewrite mitigations in December. May we issue a polite reminder about the importance of applying patches instead of temporary mitigation?
Back to the chatter. The third- and fourth-most-discussed flaws over the quarter were found in Fortinet’s FortiOS (CVE-2022-40684 and CVE-2022-42475).
Figure 2: Q4 2022’s most-discussed vulnerabilities
The chatter wasn’t light: Threat actors went as far as sharing proof-of-concept (PoC) exploits on criminal forums and discussed their many attempts at exploitation. That kind of sharing is pretty common. Cyber criminals are often quick to develop exploit codes after high-severity vulnerabilities are disclosed, and they often share them for free on criminal forums. So, exploitation in the wild often follows a flaw’s disclosure.
We saw many instances of threat actors sharing PoCs in the past quarter. On November 21, 2022, a moderator of the popular Russian-language cyber criminal forum XSS shared a PoC for the ProxyNotShell vulnerabilities (see Figure 3).
Figure 3: XSS moderator sharing PoC for ProxyNotShell
If a PoC isn’t offered up straightaway, it’s sometimes just a matter of time and persistence: Figure 4 shows a request from a cyber criminal for a PoC.
Figure 4: Exploit forum user asking for exploit for FortiOS SSL-VPN vulnerability
Old but Gold: Exposed Infrastructure
The ReliaQuest Photon Research team observed many attack attempts on our clients’ exposed infrastructure (see Figure 5). Those generating the most alerts were CVE-2012-2336 and CVE-2012-2311.
Figure 5: CVEs used to target exposed infrastructure in Q4 2022
Exposed infrastructure can include domains, cloud services, and web applications. Infrastructure often has to be exposed so that customers can interact with it. But threat actors have their own plans for interaction, attempting attacks to access sensitive data that the infrastructure offers up. Popular attack methods include SQL injection, directory transversal, and privilege escalation.
In Q4 2022, attackers mostly went after years-old vulnerabilities, which still pose a high threat to organizations, if not patched. Security teams have been known to sleep on old vulnerabilities, especially those with low CVSS scores, so exploitation attempts are rife even long after patches arrive. Threat actors delight in finding an organization that delays patching, uses legacy systems, and exhibits a high risk appetite.
What’s worse, exploits are typically freely available to threat actors, and they don’t require much technical knowledge to use.
2022: A Very Vulnerable Year
So that’s CVEs in the fourth quarter. Let’s zoom out to look at the whole of 2022: a year in which 24,230 new vulnerabilities were discovered (see Figure 6). The majority of these were privilege-escalation vulnerabilities, followed by memory corruption, cross-site scripting (XSS), information disclosure, and denial of service. Privilege escalation flaws are popular because they can allow higher levels of permissions (e.g., administrator or system level), which greases the wheels of attacks.
Figure 6: Number of vulnerabilities discovered in 2022, by type
Based on data we gathered, Log4Shell (CVE-2021-44228) was the vulnerability that generated the most alerts for our clients in 2022. In second place came the Follina zero-day vulnerability (CVE-2022-30190), and in third and fourth were those ProxyNotShell vulnerabilities (see Figure 7). It came as no surprise that threat actors leaped at opportunities to exploit these high-profile vulnerabilities all year long.
Figure 7: Vulnerabilities exploited to attack organizations in 2022
Future Flaws: The Q1 2023 Forecast
We anticipate that 2023 will bring many new vulnerabilities, some of which may keep security teams up at night and working into the weekend—it’s not uncommon for attacks to occur at times inconvenient for security teams. And it’s no coincidence that many new CVEs are disclosed on weekends, or right before holiday breaks. Remember Log4Shell?
Sophisticated cyber criminals (nation-state threat actors and ransomware operators, we’re looking at you) often exploit new flaws first, as we saw in 2022. It typically doesn’t take long for exploitation to begin in the wild, with busy threat actors quickly researching new flaws, developing PoC exploits, then sharing or selling them to their peers. We expect a jump in cyber-criminal collaboration in 2023. Staying on top of cyber-criminal activity will be key to bringing context to vulnerability intelligence.
A vulnerability discussed on news websites and social media typically becomes a hot topic on criminal forums, eventually making its way into threat actors’ arsenals. At ReliaQuest we monitor cyber-criminal activities in underground forums and their discussions of vulnerabilities and PoC exploits. We also analyze the data linked to attack attempts. We use all that information to give our customers actionable vulnerability intelligence.
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