In the Linux kernel, a critical vulnerability has been resolved, classified as a high-severity use-after-free issue related to the tcp/dccp protocol. This vulnerability arises from the improper use of the timer_pending() function within the reqsk_queue_unlink() function, as reported by Martin KaFai Lau.
The vulnerability's severity, rated at CVSS 7.0, indicates significant risk to organizations. Attackers may leverage this flaw to achieve unauthorized access or cause service disruptions, making it imperative for defenders to take immediate action. The published date of November 7, 2024, marks a critical point for remediation efforts.
Risk to organizations includes potential exploitation scenarios where attackers could execute arbitrary code, leading to unauthorized data access or system crashes. Organizations should prioritize patching immediately to mitigate these risks.
Currently, there is no known public exploit or proof of concept associated with this vulnerability. However, the nature of the flaw and its implications highlight the urgency for organizations to address it within their patch management cycles.
Given the potential impact and the high CVSS score, organizations should address this vulnerability in their priority patch cycle.
Vulnerability Details
This vulnerability allows for a use-after-free condition in the Linux kernel's tcp/dccp implementation. The vulnerability arises from a missed call to del_timer_sync() due to improper usage of timer_pending(), leading to a race condition that can be exploited in certain scenarios.
The vulnerability has a CVSS base score of 7.0, indicating high severity. It affects the Linux kernel versions from 4.1.11 to 6.12-rc3, with the last modification date noted as November 3, 2025.
The official CWE classification for this issue is CWE-416, which denotes a use-after-free vulnerability. Organizations running affected versions of the Linux kernel should be aware of their risk exposure.
Technical Analysis
The root cause of this vulnerability stems from a race condition triggered by the inappropriate use of the timer_pending() function in the reqsk_queue_unlink() method. When the reqsk timer is scheduled to run, it may still be active even after the associated socket structure has been freed, leading to a use-after-free condition.
The attack vector for this vulnerability is local, requiring low privileges for exploitation. The attack complexity is rated as high, indicating that successful exploitation would require specific conditions to be met.
No user interaction is required for the exploit to be executed. The impacts include high confidentiality, integrity, and availability risks, as the vulnerability could allow attackers to execute arbitrary code within the kernel context.
Risk & Impact Analysis
The real-world deployment risk associated with this vulnerability is significant. Organizations utilizing affected Linux kernel versions are at risk of exploitation, which could lead to unauthorized access, data breaches, or service disruptions. The blast radius could be extensive, impacting systems that rely on the Linux kernel, potentially affecting various services and applications.
Organizations should assess their exposure to this vulnerability and prioritize remediation efforts based on the CVSS score and the potential impact on their operations. The urgency for addressing this vulnerability is high due to its exploitability and the critical nature of the systems involved.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following versions of the Linux kernel are affected by this vulnerability: 4.1.11 through 4.2, 4.2 through 5.15.170, 5.16 through 6.1.115, 6.2 through 6.6.59, and 6.7 through 6.11.6, along with release candidates 6.12:rc1, 6.12:rc2, and 6.12:rc3.
Mitigation & Remediation
To remediate this vulnerability, organizations should apply the latest patches provided by the Linux development team. It is crucial to monitor the official repositories for updates and ensure that systems are upgraded to fixed versions.
If immediate patching is not feasible, organizations can mitigate the risk by implementing additional security controls, such as restricting access to vulnerable components and monitoring system logs for unusual activity.
For comprehensive security, organizations should consider regular security assessments and penetration testing to uncover and address potential vulnerabilities.
Organizations should validate remediation through penetration testing to identify similar weaknesses.
Detection Guidance
Organizations should monitor system logs for indicators of compromise related to this vulnerability. Look for anomalies in network traffic that may suggest exploitation attempts.
Behavioral anomalies in network interactions, particularly involving the TCP stack, should be investigated thoroughly to detect potential abuse of the affected kernel functionalities.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability lies in its potential exploitation as a vector for further attacks against affected systems. It represents a broader trend of vulnerabilities in kernel-level code that can yield significant access to system resources.
Security teams should focus on proactive measures to secure kernel implementations and conduct regular audits to identify vulnerabilities. This incident underscores the importance of maintaining up-to-date software and continuous security validation.
For further reading on vulnerability management and penetration testing, refer to our guides on vulnerability management programs and penetration testing methodologies to strengthen your organization's security posture.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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