In the Linux kernel, a medium-severity vulnerability has been resolved which can lead to high availability impact. The issue arises from a flaw in the graphics driver (drm/xe) related to TLB invalidation when wedging. Specifically, if the GuC fails to load, the driver could attempt operations on uninitialized variables, leading to a NULL pointer dereference. This vulnerability could be easily triggered, and if exploited, may disrupt kernel operations, causing significant instability.
The vulnerability has been assigned a CVSS score of 5.5, categorizing it as medium severity. This indicates a low attack complexity and low privileges required, making it relatively easier for potential attackers to exploit the vulnerability under certain conditions.
Risk to organizations includes potential system crashes and data loss. Given the availability impact is high, organizations running vulnerable versions of the Linux kernel should prioritize remediation efforts to ensure system integrity and uptime.
Organizations should address this vulnerability in their priority patch cycle. The vulnerability was published on January 19, 2025, and has been marked as modified, indicating that additional details or fixes may have been introduced since its initial disclosure.
Vulnerability Details
The official description of the vulnerability states that the issue consists of a flaw in the Linux kernel's graphics driver, specifically under the drm/xe component. The problem is linked to TLB invalidation during wedging operations. When the GuC fails to load, it can cause the driver to operate on uninitialized variables, leading to a NULL pointer dereference.
The CVSS score assigned to this vulnerability is 5.5, indicating a medium severity level. The attack vector is local, requiring access to the vulnerable system, while the attack complexity is low, and privileges required are also low. There is no user interaction needed to exploit this vulnerability. Moreover, the availability impact is high, suggesting that a successful exploitation could lead to significant system downtime.
Affected products include various versions of the Linux kernel, particularly versions from 6.11 up to but not including 6.12.10, as well as several release candidates of version 6.13. The vulnerability was published on January 19, 2025, and is classified under CWE-476: NULL Pointer Dereference.
Technical Analysis
The root cause of the vulnerability lies in the initialization sequence of the graphics driver. When the GuC fails to load, the driver attempts to proceed with operations that rely on uninitialized data structures, specifically during TLB invalidation. This can lead to a NULL pointer dereference, which causes the kernel to crash.
The attack vector is local, meaning an attacker would need to have access to the system running the vulnerable kernel. The attack complexity is low, and the privileges required are also low, which means that a user with basic access could potentially exploit this vulnerability without needing elevated permissions.
No user interaction is required to trigger this vulnerability, making it easier for potential attackers to exploit it. In terms of impact, while confidentiality and integrity are unaffected, the availability impact is rated as high, indicating that the system could become unusable if the vulnerability is successfully exploited.
Risk & Impact Analysis
The real-world deployment risk of this vulnerability is significant, particularly for organizations that rely on the Linux kernel for critical infrastructure. If exploited, this vulnerability could result in unexpected system crashes, leading to downtime and potential data loss, which can have severe implications for business operations.
The blast radius potential is broad as many systems utilize the Linux kernel, and the impact could be felt across various sectors. Organizations that have not yet patched this vulnerability may find themselves at risk, especially given the ease with which it can be triggered.
Based on the CVSS score and the fact that this vulnerability is not included in the Known Exploited Vulnerabilities (KEV) catalog, organizations should schedule remediation in their patch cycles to mitigate risks associated with this vulnerability.
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:
All versions from 6.11 up to, but not including, 6.12.10, as well as several release candidates of version 6.13 (rc1 through rc6) are vulnerable.
Mitigation & Remediation
Organizations should prioritize patching this vulnerability immediately. The recommended action is to upgrade to a patched version of the Linux kernel that addresses this issue. For those unable to apply the patch right away, mitigating strategies include disabling the affected driver or limiting access to the system until a patch can be applied.
For detailed guidance on security testing and vulnerability management, organizations can refer to the penetration testing services available.
Detection Guidance
To effectively monitor for this vulnerability, organizations should enable logging for the Linux kernel and monitor for abnormal error messages related to driver loading and TLB invalidation. Additionally, behavioral anomalies in system performance following driver updates should be tracked as potential indicators of exploitation.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2025-21644 highlights the ongoing risks associated with driver vulnerabilities in the Linux kernel. Security teams should recognize the importance of timely patching and the need for proactive identification of vulnerabilities in their systems. This incident underscores the necessity for effective vulnerability management programs.
Security professionals are encouraged to review their systems regularly for vulnerabilities and consider implementing robust security frameworks. For further reading on vulnerability management best practices, refer to our article on vulnerability management program design and the importance of continuous security assessments.
Additionally, organizations can benefit from understanding the role of penetration testing in identifying and mitigating such vulnerabilities, as discussed in our guide on penetration testing methodology.
By staying informed and implementing best practices, organizations can significantly reduce their risk exposure to vulnerabilities like CVE-2025-21644.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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