Vulnerabilities in Xine-Lib and Mplayer

The vulnerability in Mplayer was disclosed just recently; further information is available from the project hompage for the player. The vulnerabilities were discovered in part by Core Security. One of the vulnerabilities was inherited by Xine-Lib. Other applications based on Mplayer, or the Xine library may be affected. Security researchers classify both vulnerabilities in both projects as extremely critical.

The vulnerability, which affects both Mplayer and Xine-Library, can be exploited by injecting manipulated comments in loss-free FLAC compressed files (Free Lossless Audio Codec). The attacker can use this vector to provoke a stack overflow in the "demux_audio.c" file, and then run injected code with the player's UID.

Based on current findings, only Mplayer and projects based on it are affected by the bug. Attackers can use some IPv6 URLs to provoke a buffer overflow in the "stream/url.c" file's "url_escape_string" function. An array indexing error in "demux_mov.c" can also provoke a buffer overflow on parsing MOV files. Additionally, a buffer overflow can occur on evaluating CDDB files.

The vulnerabilities affect Xine-Lib up to version 1.1.10 and Mplayer up to version 1.0rc2. The Mplayer team has released patches to remedy the situation. Distributors are likely to follow suit with updated packages in the next few days.