In the Linux kernel, the following vulnerability has been resolved: net: netlink: af_netlink: Prevent empty skb by adding a check on len. This vulnerability allows a division error in the netem_enqueue function which is caused when skb->len=0 and skb->data_len=0 during a corruption step. As a result, organizations using affected versions of the Linux kernel are at risk of system crashes.
The severity of this vulnerability is classified as medium with a CVSS score of 5.5. The risk to organizations includes potential service disruptions due to system crashes, particularly affecting availability. Therefore, organizations should prioritize patching immediately.
Currently, there are no known exploits or proof of concept available for this vulnerability. However, the fact that it is present in the kernel code means that any local attacker could potentially exploit it under the right conditions.
Organizations should address this vulnerability in their priority patch cycle, ensuring that they apply the latest updates to mitigate risks effectively.
Vulnerability Details
The vulnerability is a result of inadequate input validation in the Linux kernel, specifically within the netlink subsystem. The addition of a check on the length parameter helps prevent empty socket buffers (skbs) from causing division errors in the netem_enqueue function, which can lead to crashes.
The CVSS score of 5.5 indicates a medium severity level, suggesting that while the impact may not be critical, it can still lead to significant service interruptions.
Technical Analysis
The root cause of this vulnerability stems from the Linux kernel's handling of netlink messages. Specifically, when the length of the skb is zero, the function does not properly validate this input, leading to a division error when attempting to manipulate the socket buffer data. This can occur locally, as the attack vector is classified as local with low complexity.
No user interaction is required for this attack, and the privileges required to exploit this vulnerability are low, meaning that a standard user account on the system could potentially trigger the condition leading to a crash.
Risk & Impact Analysis
The real-world deployment risk associated with this vulnerability is associated with potential system crashes, which could result in downtime and loss of availability. Organizations using affected Linux kernel versions should be particularly concerned about the integrity and availability impacts of this issue.
Given the CVSS score of 5.5 and the lack of known exploits or active targeting, organizations should prioritize patching this vulnerability in their maintenance schedules to reduce exposure.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerable versions of the Linux kernel include all versions prior to 4.4.296, as well as ranges from 4.5 to 4.9.294, 4.10 to 4.14.259, 4.15 to 4.19.222, 4.20 to 5.4.167, 5.5 to 5.10.87, and 5.11 to 5.15.10. Additionally, specific release candidates (rc1, rc2, rc3) for version 5.16 are also affected.
Mitigation & Remediation
Organizations should ensure they apply the latest patches to the Linux kernel as soon as they become available. Version upgrades should be pursued to mitigate this vulnerability effectively. If patches are unavailable, consider implementing network controls to limit the potential impact of exploitation.
For further guidance on effective security practices, organizations may consult resources on penetration testing and monitoring recommendations.
Detection Guidance
Organizations should monitor logs for indicators of anomalies related to netlink messaging and system crashes. Behavioral anomalies triggering frequent kernel panics may also indicate attempts to exploit this vulnerability.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability highlights the need for robust input validation in kernel-level code. It represents ongoing trends within the Linux kernel community to address vulnerabilities proactively and enhance stability.
Security teams should take this as a lesson in the importance of thorough testing and validation in development processes to prevent similar vulnerabilities from being introduced in the future.
For additional reading on secure coding practices, organizations can explore the secure coding practices guide and other relevant resources.
Furthermore, engaging in penetration testing methodology can help organizations uncover similar vulnerabilities before they are exploited.
Lastly, understanding the evolving landscape of vulnerabilities, such as those detailed in the vulnerability management program will be crucial for effective risk management.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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