CVE-2022-43239 is a heap-buffer-overflow vulnerability identified in libde265 version 1.0.8, specifically within the mc_chroma<unsigned short> function in the motion.cc source file. Libde265 is an open-source H.265/HEVC video decoder library used in various multimedia applications and platforms to decode video streams encoded with the HEVC standard. The vulnerability arises when processing crafted video files that exploit improper bounds checking, leading to a heap buffer overflow condition. This flaw can be triggered remotely by an attacker supplying a maliciously crafted video file, causing the application using libde265 to crash or become unresponsive, resulting in a Denial of Service (DoS). The CVSS v3.1 base score is 6.5 (medium severity), with the vector indicating that the attack can be performed remotely (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R), and impacts availability only (A:H) without affecting confidentiality or integrity. No known exploits are reported in the wild, and no official patches or vendor advisories are currently linked, indicating that mitigation may rely on updating libde265 to a fixed version once available or applying custom patches. The vulnerability is classified under CWE-787 (Out-of-bounds Write), a common and critical class of memory corruption bugs that can lead to crashes or potentially more severe exploitation if combined with other vulnerabilities.

For European organizations, the primary impact of this vulnerability is the potential disruption of services that rely on libde265 for video decoding, such as media streaming platforms, video conferencing tools, digital signage systems, and multimedia processing pipelines. A successful exploitation leads to Denial of Service, which can degrade user experience, interrupt business operations, and cause reputational damage, especially for service providers and enterprises with customer-facing video services. Although this vulnerability does not directly compromise data confidentiality or integrity, the availability impact can be significant in environments where video processing is critical. Additionally, the requirement for user interaction (e.g., opening a crafted video file) means that social engineering or phishing could be vectors for exploitation. European organizations with multimedia applications embedded in their products or services, including broadcasters, telecommunication companies, and software vendors, should be particularly vigilant. The absence of known exploits reduces immediate risk but does not eliminate the threat, as attackers may develop exploits over time.

1. Monitor for official patches or updates to libde265 and apply them promptly once available. 2. Until patches are released, consider implementing input validation and sandboxing techniques to isolate video decoding processes, limiting the impact of potential crashes. 3. Employ application-level mitigations such as disabling automatic playback of untrusted video files or restricting the types of video files accepted from untrusted sources. 4. Educate users about the risks of opening video files from unknown or untrusted origins to reduce the likelihood of exploitation via social engineering. 5. Use runtime protection tools like AddressSanitizer or other memory error detection mechanisms during development and testing to detect similar vulnerabilities. 6. For organizations developing software that uses libde265, consider auditing and hardening the integration points and possibly replacing libde265 with alternative decoders if timely patches are not forthcoming. 7. Implement robust logging and monitoring to detect abnormal application crashes or service disruptions that may indicate exploitation attempts.