Software Engineering Institute

MPlayer is a movie player for Linux and other Unix-based operating systems. MPlayer fails to properly allocate a memory buffer for URL strings containing characters that need to be escaped. When escaping characters in a URL, a single character may be replaced by three. For instance, the space character may be replaced by %20. There is a vulnerability in the way MPlayer allocates memory to store the escaped representation of the URL. By sending a "Location" HTTP header containing an overly long URL with many un-escaped characters, an attacker can trigger a buffer overflow.

According to the MPlayer Advisory, the following versions are affected:

• MPlayer 0.90pre series
• MPlayer 0.90rc series
• MPlayer 0.90
• MPlayer 0.91
• MPlayer 1.0pre1
• MPlayer 1.0pre2
• MPlayer 1.0pre3

By convincing a user to play a media file containing a specially crafted "Location" HTTP header, an attacker could cause MPlayer to crash or potentially execute code of the attacker's choice with privileges of the victim.

UpgradeAccording to the MPlayer Advisory, users of MPlayer 1.0pre3 should upgrade to the latest CVS. MPlayer 0.92 (and below) users should upgrade to 0.92.1 or the latest CVS.

Apply Patch

Apply a patch as specified by your vendor. If a patch is unavailable from your vendor, the maintainers of MPlayer have provided a patch for all vulnerable versions. This patch can be obtained from:

http://www.mplayerhq.hu/MPlayer/patches/vuln02-fix.diff