CVE-2021-47348 is a critical vulnerability in the Linux kernel related to the HDCP (High-bandwidth Digital Content Protection) protocol. This vulnerability allows for potential corruption of data due to improper handling of buffer sizes. Specifically, instead of reading the desired 5 bytes, the code erroneously reads 8 bytes, which can lead to a corrupted value if the trailing bytes contain non-zero values. The severity of this vulnerability is highlighted by its CVSS score of 9.1, categorizing it as critical.
Risk to organizations includes potential data corruption and the impact on the availability of services relying on the affected kernel components. Given the critical nature of the vulnerability, organizations that utilize the Linux kernel in their systems should urgently address this issue to prevent exploitation.
As of now, there is no known public exploit available for this vulnerability, but the nature of the issue combined with its critical severity means that organizations should prioritize patching immediately. The vulnerability has been resolved in patches released as of May 21, 2024, and organizations are encouraged to implement these updates without delay.
This vulnerability underscores the importance of rigorous security practices and timely updates within the Linux kernel ecosystem, especially for systems that manage sensitive data or critical infrastructure.
Vulnerability Details
The official description identifies that in the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Avoid HDCP over-read and corruption. The improper read operation could lead to a corrupted value if the trailing bytes are non-zero, necessitating the use of an appropriately sized and zero-initialized bounce buffer.
The vulnerability is classified as CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer). It affects the Linux kernel versions prior to 5.10.51, starting from versions 5.11 to less than 5.12.18, and from 5.13 to less than 5.13.3.
Technical Analysis
The root cause of this vulnerability lies in the improper handling of buffer sizes during HDCP operations within the Linux kernel. Specifically, the code attempts to read too many bytes from a buffer, which can lead to data corruption if the additional bytes contain non-zero values. The attack vector for this vulnerability is over the network, with low complexity requiring no privileges or user interaction. The confidentiality impact is high, and the availability impact is also high, as the corruption could affect system functionality.
Risk & Impact Analysis
Real-world deployment of this vulnerability poses a significant risk due to the potential for data corruption and service disruption. Organizations utilizing the affected Linux kernel versions must prioritize remediation to mitigate the risk of exploitation. The blast radius for this vulnerability could be extensive, affecting any system that relies on the Linux kernel for operations. Given the high CVSS score and the lack of known public exploits, organizations should address this vulnerability in their priority patch cycle.
Exploitation Status
Signal | Status |
|---|---|
Known Exploit | No |
Public PoC | No |
Actively Exploited | No |
Ransomware Use | No |
Affected Versions
The vulnerability affects all Linux kernel versions prior to 5.10.51, as well as versions 5.11 to less than 5.12.18 and from 5.13 to less than 5.13.3. Organizations must ensure they are operating on patched versions.
Mitigation & Remediation
Organizations should prioritize upgrading to the latest Linux kernel versions to mitigate this vulnerability. If a patch is not yet applied, workarounds may include implementing strict access controls and monitoring for unusual behaviors. Additionally, organizations can implement configuration hardening around the affected systems.
For additional guidance on effective vulnerability management, organizations may consider reviewing our resource on vulnerability management programs and implement continuous security testing strategies.
Detection Guidance
Organizations should implement logging mechanisms to capture any anomalies related to kernel operations. Monitoring network traffic for unusual patterns can also indicate potential exploitation attempts. It is vital to ensure that system configurations are regularly reviewed for compliance with security policies.
AppSecure Threat Intelligence Insight
This vulnerability serves as a reminder of the critical nature of kernel security within the broader context of system security. The trends surrounding kernel vulnerabilities indicate a growing need for organizations to adopt proactive security measures. Security teams should focus on comprehensive assessments and consider engaging in penetration testing services to identify potential weaknesses. Furthermore, organizations can benefit from reviewing our insights on penetration testing methodologies and applying lessons learned from previous incidents.
Organizations should also remain vigilant about the evolving threat landscape and consider adopting a vulnerability management program to ensure ongoing protection.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
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