CVE-2015-4496

Vulnerability

Multiple integer overflows exist in the libstagefright library used by Mozilla Firefox for parsing MPEG-4 video files. These flaws occur when processing crafted sample metadata in MP4 containers. The vulnerability affects Firefox versions prior to 38.0 and SeaMonkey versions prior to 2.35 [2]. No special configuration is required; the code path is triggered when Firefox attempts to play or render a malicious MP4 file.

Exploitation

An attacker can exploit this by crafting a malicious MPEG-4 video file containing specially crafted sample metadata. The attacker must then deliver this file to the victim, typically via a webpage or email attachment. No authentication or user interaction beyond opening the file is required. The integer overflows lead to memory corruption that can be leveraged to achieve arbitrary code execution.

Impact

Successful exploitation allows the attacker to execute arbitrary code with the privileges of the Firefox process. This can result in full compromise of the affected system, including data theft, installation of malware, or further lateral movement. The severity is rated Critical by Mozilla [2].

Mitigation

The vulnerability is fixed in Firefox 38.0 and SeaMonkey 2.35, released on August 12, 2015 [2]. Users should update to these versions or later. No workarounds are documented. Mozilla has confirmed the fix in source code [1][3] and awarded a security bounty for the report.