CVE-2023-47359: 
VLC media player vulnerability analysis and mitigation

Videolan VLC media player versions prior to 3.0.20 contain a critical heap-based buffer overflow vulnerability in the MMS (Microsoft Media Server) protocol implementation. The vulnerability, identified as CVE-2023-47359, stems from an incorrect offset read in the GetPacket() function that leads to memory corruption. The issue was discovered and reported on September 1, 2023, and was fixed in VLC version 3.0.20 released on October 30, 2023 (VLC Blog).

The vulnerability exists in the MMSH (MMS over HTTP) module's packet handling mechanism. When calculating the remaining size of the packet to read, the code decreases 8 bytes instead of the required 12 bytes (size of already read headers). The calculation pck->idata = pck->isize2 - 8 leads to a potential heap buffer overflow. The size being read is capped to i_size2 = 0xffff - 8 = 0xfff7, and with the buffer size being 0x10001 (65537 bytes), this results in a buffer overflow condition. The vulnerability has been assigned a CVSS v3.1 base score of 9.8 (Critical) (NVD).

The vulnerability allows remote attackers to potentially execute arbitrary code or cause denial of service through specially crafted media files. When successfully exploited, the buffer overflow can lead to memory corruption and potential system compromise (Ubuntu Security).

The vulnerability has been fixed in VLC version 3.0.20. Users are strongly advised to update to this version or later. Multiple Linux distributions have also released security updates to address this vulnerability, including Ubuntu 23.10 (3.0.18-4ubuntu0.1), Ubuntu 22.04 LTS (3.0.16-1ubuntu0.1~esm2), and Debian (3.0.20-0+deb10u1) (Ubuntu Security, Debian Security).