CVE-2022-3924 represents a high-severity vulnerability affecting ISC BIND resolvers that are configured with `stale-answer-enable yes;` and utilize the `stale-answer-client-timeout` option set to a value greater than zero. This issue could lead to assertion failures during high-load scenarios where many clients are waiting for recursive queries to complete.
The vulnerability occurs when the resolver must SERVFAIL the longest waiting client due to the arrival of a new query. A race condition may arise between providing a stale answer and sending an early timeout SERVFAIL, resulting in potential instability for the resolver. This vulnerability affects BIND 9 versions 9.16.12 to 9.16.36, 9.18.0 to 9.18.10, and 9.19.0 to 9.19.8.
Organizations utilizing affected versions should prioritize patching, given the high CVSS score of 7.5, which denotes significant availability impact. The potential for assertion failures poses a risk to the stability of BIND services, making this vulnerability critical to address.
Currently, there are no known exploits or public proof of concepts available for this vulnerability, but organizations must not rely on this status as a guarantee of safety.
Vulnerability Details
The official CVE description notes that BIND 9 resolvers with specific configurations are vulnerable to assertion failures under certain conditions. The impact is a high likelihood of service disruptions, especially in environments with high query loads.
Technical Analysis
The root cause of this vulnerability stems from how BIND handles stale answers in a high-load scenario. The resolver's configuration allows for multiple clients waiting for recursion, potentially leading to timing issues when managing responses.
The attack vector is network-based, with low complexity, requiring no privileges or user interaction. The availability impact is rated high, indicating that exploitation could cause significant service interruptions.
Risk & Impact Analysis
Risk to organizations includes potential service outages and degraded performance of DNS services. The blast radius could extend to any dependent services that rely on BIND for name resolution, affecting user access and application functionality.
Given the current threat landscape and the high CVSS score, organizations should prioritize patching immediately. Even without known exploits, the nature of the vulnerability warrants urgent attention.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
This vulnerability affects BIND 9 versions 9.16.12 through 9.16.36, 9.18.0 through 9.18.10, 9.19.0 through 9.19.8, and specific versions marked with S1. Organizations should ensure they upgrade to the latest patched versions.
Mitigation & Remediation
Organizations should patch affected systems to remediate this vulnerability. The latest versions of BIND should be deployed to avoid potential assertion failures. If immediate patching is not feasible, consider configuration changes to disable stale answers until a patch can be applied.
For detailed guidance on secure configurations and testing, organizations can refer to our penetration testing services to identify weaknesses.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor logs for unusual query patterns, especially during peak loads. Behavioral anomalies in DNS resolution requests can indicate attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2022-3924 lies in its potential to disrupt critical DNS services. It highlights the importance of maintaining updated systems and implementing robust configurations to mitigate risks associated with DNS resolver vulnerabilities.
Security teams should remain vigilant regarding configuration settings and the implications of enabling features like stale answers. For comprehensive security strategies, reviewing our vulnerability management program can facilitate proactive measures against similar vulnerabilities.
Additionally, understanding the operational impacts of vulnerabilities like CVE-2022-3924 can guide organizations toward better defensive postures. Engaging in regular penetration testing is crucial to identifying and mitigating such risks before they can be exploited.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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