CVE-2021-25803: 
VLC media player vulnerability analysis and mitigation

A buffer overflow vulnerability was identified in the vlcinputattachment_New component of VideoLAN VLC Media Player 3.0.11. The vulnerability, tracked as CVE-2021-25803, allows attackers to cause an out-of-bounds read through a specially crafted .avi file. The issue was discovered and initially recorded on January 22, 2021 (CVE Mitre).

The vulnerability stems from an integer overflow in the AVI file processing component of VLC Media Player. This overflow leads to a size verification failure, which subsequently results in a buffer overflow condition. The issue was identified by Zhen Zhou from the NSFOCUS Security Team and was addressed in the VLC codebase (VLC Commit).

When exploited, this vulnerability could cause VLC Media Player to crash, resulting in a denial of service condition. The vulnerability specifically affects systems when processing maliciously crafted AVI video files (Ubuntu Notice).

The vulnerability has been fixed in subsequent releases of VLC Media Player. Various Linux distributions have released security updates to address this issue, including Debian which fixed it in version 3.0.12-1 and Ubuntu which provided patches across multiple versions of their distribution (Debian Tracker).