In the Linux kernel, a vulnerability has been identified related to the incorrect parsing of DCB_ATTR_BCN in the dcbnl_bcn_setcfg function. This issue arises from an erroneous policy that was introduced in a previous commit, potentially leading to high availability impact. The vulnerability has a CVSS score of 5.5, classifying it as medium severity. Organizations utilizing affected versions of the Linux kernel should consider this vulnerability seriously as it poses risks that could affect availability.
The root cause of this vulnerability is a programming error within the kernel's networking subsystem, specifically in the DCB (Data Center Bridging) implementation. The issue occurs when the dcbnl_bcn_setcfg function incorrectly uses a policy intended for a different set of attributes, which can lead to an overflow condition. Given the local attack vector and low complexity, it is crucial for organizations to address this vulnerability to ensure the stability of their systems.
Organizations are advised to check their systems for affected kernel versions and prioritize patching to mitigate this vulnerability effectively. The potential impact on availability could disrupt services, emphasizing the need for timely action.
As of now, there are no known exploits associated with this vulnerability, but the nature of the issue warrants immediate attention to prevent any possible future exploitation.
Vulnerability Details
This vulnerability allows for a potential overflow condition in the kernel's DCB implementation, specifically concerning the handling of the DCB_ATTR_BCN attribute. The vulnerability was introduced in the Linux kernel and has been classified as medium severity with a CVSS score of 5.5. The affected product is the Linux kernel, with the publication date of the vulnerability being September 18, 2025.
Technical Analysis
The root cause of the vulnerability lies in the incorrect policy used for parsing attributes in the dcbnl_bcn_setcfg function. The function erroneously employs a policy designed for DCB_PFC_UP attributes instead of the correct DCB_BCN attributes. This misconfiguration can lead to an overflow of the dcbnl_pfc_up_nest and subsequently affect the parsing of DCB_BCN attributes.
The attack vector is local, requiring low privileges to exploit. No user interaction is required, making the vulnerability easier to exploit under the right conditions. The availability impact is classified as high, while confidentiality and integrity impacts are deemed none.
Risk & Impact Analysis
Risk to organizations includes potential disruptions in service availability due to the overflow condition in the DCB implementation. If exploited, this vulnerability may lead to significant operational impacts, especially in environments relying on the Linux kernel for critical services. The medium severity and CVSS score of 5.5 suggest that organizations should address this vulnerability in their patch management processes.
Given the nature of this vulnerability, organizations should prioritize patching immediately. The availability impact could have a cascading effect on network performance and service delivery.
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
Affected versions include multiple releases of the Linux kernel, specifically those from version 2.6.29 up to 5.4.253, 5.5 up to 5.10.190, 5.11 up to 5.15.126, 5.16 up to 6.1.45, and 6.2 up to 6.4.10, as well as specific release candidates 6.5:rc1 through 6.5:rc4.
Mitigation & Remediation
Organizations should prioritize patching to the latest versions of the Linux kernel to address this vulnerability. This includes updating to versions beyond 5.4.253, 5.10.190, 5.15.126, 6.1.45, and 6.4.10 as applicable. If immediate patching is not feasible, consider implementing network controls and segmentation to limit exposure while appropriate remediations are put in place.
For further guidance, organizations can refer to our comprehensive resources on penetration testing to validate their patching and configuration efforts.
Detection Guidance
Organizations should monitor logs for any unusual activity related to the DCB functionality in the Linux kernel, particularly any attempts to exploit the DCB_ATTR_BCN attribute. Behavioral anomalies in network traffic should also be analyzed for signs of exploitation.
AppSecure Threat Intelligence Insight
The long-term significance of this vulnerability highlights the importance of robust testing and validation processes within the development lifecycle of the Linux kernel. It also reflects a pattern of misconfiguration issues that can lead to vulnerabilities. Security teams should take this as a strategic reminder to implement thorough code reviews and testing protocols.
To further bolster security measures, organizations should consider adopting a penetration testing methodology that not only identifies existing vulnerabilities but also fortifies their defenses against potential future threats.
Additionally, engaging in a vulnerability management program can help organizations stay ahead of emerging vulnerabilities, ensuring that they have the necessary processes and tools in place.
Finally, organizations should remain vigilant in exploring the landscape of threats, particularly as it relates to the Linux kernel, to inform their security strategies and response plans.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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