In the Linux kernel, a vulnerability has been identified that allows for a use-after-free condition when Universal DVB cards are detached. Specifically, the function netup_unidvb_dma_fini() attempts to stop a timer with del_timer() while the timer handler netup_unidvb_dma_timeout() is still running. This can lead to the potential exploitation of freed memory, causing instability or unauthorized access.
The CVSS score for this vulnerability is 7.8, classified as high severity. This score indicates a local attack vector with low complexity and requires low privileges, making it accessible to standard users. The impacts on confidentiality, integrity, and availability are all rated high, underscoring the potential for significant damage.
Risk to organizations includes the potential for system crashes, unauthorized access to sensitive data, and service disruptions. Given the local attack vector, attackers with minimal privileges could exploit this vulnerability, leading to severe operational impacts. Therefore, organizations should prioritize patching immediately to mitigate these risks.
Currently, there are no known exploits or public proof-of-concept available for this vulnerability, but the nature of the issue necessitates immediate attention. Organizations utilizing affected versions of the Linux kernel should ensure timely remediation to maintain security integrity.
Vulnerability Details
The vulnerability is identified as CVE-2023-53219 and is classified under CWE-416, which pertains to use-after-free errors. The Linux kernel versions affected include those from 4.3 to 6.3.4, with specific exclusions for patches released after these versions. The vulnerability was published on September 15, 2025, and has been modified as of January 14, 2026.
Technical Analysis
The root cause of this vulnerability is the improper handling of a timer during the detachment process of a Universal DVB card. When the cleanup routine attempts to stop the dma->timeout timer using del_timer(), it does not synchronize correctly with the timer routine that might still be executing, leading to the potential use-after-free condition.
The attack vector is local, requiring the attacker to have physical or administrative access to the system. The complexity of the attack is low, and it does not require user interaction, making it easier to exploit. The consequences of a successful exploitation include high impacts on confidentiality, integrity, and availability due to the nature of the memory being accessed.
Risk & Impact Analysis
This vulnerability poses a significant risk to organizations that rely on the Linux kernel for their operations. The potential for unauthorized access to sensitive information, system crashes, or other disruptions can have far-reaching consequences. The urgency for remediation is heightened by the high CVSS score and the potential for exploitation by standard users with low privileges.
Given that the vulnerability affects a broad range of kernel versions, organizations should assess their systems for exposure and prioritize patching as part of their security strategy. The lack of publicly known exploits does not diminish the need for immediate action, as the vulnerability can still be exploited under certain conditions.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The following Linux kernel versions are affected by this vulnerability: all versions from 4.3 to 4.14.316, 4.15 to 4.19.284, 4.20 to 5.4.244, 5.5 to 5.10.181, 5.11 to 5.15.113, 5.16 to 6.1.30, and 6.2 to 6.3.4. Additionally, versions 6.4:rc1 and 6.4:rc2 are also vulnerable.
Mitigation & Remediation
Organizations should apply updates to the Linux kernel immediately to mitigate this vulnerability. The fix involves replacing the del_timer() function with del_timer_sync() in the affected code paths. For systems where immediate patching is not possible, consider implementing configuration hardening and network controls to limit exposure.
For further guidance on security testing, organizations can refer to the comprehensive penetration testing services available.
Detection Guidance
To detect potential exploitation of this vulnerability, organizations should monitor log indicators for unusual timer-related activities and behavioral anomalies in the kernel space. Additionally, network signatures indicative of unexpected behavior during the detachment of Universal DVB cards should be implemented.
AppSecure Threat Intelligence Insight
The long-term significance of CVE-2023-53219 lies in its representation of ongoing vulnerabilities within critical infrastructure components like the Linux kernel. Security teams are reminded to regularly assess their systems for similar vulnerabilities and to engage in proactive security measures.
For additional resources on vulnerability management, organizations can review the following articles: vulnerability management program and penetration testing methodology guides to strengthen your security posture.
Additionally, it is crucial for organizations to establish a robust security awareness program that emphasizes the importance of timely patching and vulnerability management.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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