CVE-2022-43239 in Libde265
Summary
by MITRE • 11/02/2022
Libde265 v1.0.8 was discovered to contain a heap-buffer-overflow vulnerability via mc_chroma<unsigned short> in motion.cc. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted video file.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 12/04/2022
The vulnerability identified as CVE-2022-43239 affects Libde265 version 1.0.8, a widely used library for decoding h.265/HEVC video streams. This library serves as a critical component in numerous multimedia applications, video players, and content delivery systems across various operating systems and platforms. The heap-buffer-overflow flaw specifically manifests within the motion compensation functionality of the decoder, particularly in the mc_chroma<unsigned short> function located in the motion.cc source file. Such a vulnerability represents a significant security concern as it can be exploited through maliciously crafted video files that trigger the buffer overflow condition during normal video decoding operations.
The technical nature of this vulnerability stems from inadequate bounds checking within the motion compensation algorithm that processes chroma samples during video frame reconstruction. When processing specially crafted video content, the mc_chroma<unsigned short> function fails to properly validate array access boundaries, allowing an attacker to write data beyond the allocated heap memory region. This heap corruption occurs during the decoding process when the library attempts to handle motion vectors and chroma interpolation for video frames. The vulnerability is classified as a heap-buffer-overflow under the Common Weakness Enumeration framework, specifically mapping to CWE-122 which describes "Heap-based Buffer Overflow" and CWE-787 which covers "Out-of-bounds Write." The flaw demonstrates characteristics consistent with the ATT&CK technique T1203 "Exploitation for Client Execution" where adversaries leverage software vulnerabilities to execute malicious code or cause system instability.
The operational impact of CVE-2022-43239 extends beyond simple denial of service, as it can be leveraged to disrupt video playback services, compromise multimedia applications, and potentially enable more sophisticated attacks if combined with other vulnerabilities. Systems utilizing Libde265 for video processing, including web browsers, media players, content management systems, and streaming platforms, become vulnerable to attack. The DoS condition can manifest as application crashes, system instability, or complete service interruption, affecting user experience and potentially enabling attackers to perform resource exhaustion attacks. Organizations deploying this library in production environments face significant risk as the vulnerability can be exploited through various attack vectors including email attachments, web downloads, or malicious streaming content, making it particularly dangerous in enterprise and consumer contexts where multimedia processing is prevalent.
Mitigation strategies for CVE-2022-43239 should prioritize immediate patching of affected Libde265 installations to version 1.0.9 or later, which contains the necessary fixes for the heap-buffer-overflow condition. System administrators should implement comprehensive monitoring for unusual application behavior or crashes related to video processing, particularly in environments where users can upload or download multimedia content. Input validation measures should be strengthened to filter potentially malicious video files before processing, while sandboxing techniques can limit the impact of successful exploitation attempts. Network-level controls including content filtering and deep packet inspection can help identify and block suspicious video content. Additionally, organizations should conduct thorough vulnerability assessments of their entire software ecosystem to identify other potential dependencies on affected versions of Libde265, implementing regular security updates and patch management protocols to prevent similar vulnerabilities from arising in the future. The vulnerability highlights the importance of robust memory safety practices in multimedia libraries and the critical need for thorough security testing of video decoding components.