The QCP file format is used by many cellular telephone manufacturers to provide ring tones and record voice. It is based on RIFF, a generic format for storing chunks of data identified by tags. The QCP format does not specify how voice data in the file is encoded. Rather, it is a container format. The detailed QCP file format is defined in RFC3625

RealPlayer is a cross-platform media player by RealNetworks that plays a number of multimedia formats including MP3, MPEG-4, QuickTime, Windows Media, QCP, and multiple versions of proprietary RealAudio and RealVideo formats.

A heap-based buffer overflow vulnerability exists in RealPlayer. Specifically, the vulnerability occurs while processing fmt chunks in QCP files. An attacker can exploit this vulnerability by enticing a user to open a specially crafted QCP file using RealPlayer. Successful exploitation would allow for arbitrary code injection and execution with the privileges of the currently logged in user. Code injection that does not result in execution would terminate the application.

The vulnerability has been assigned as CVE-2011-2950.

SonicWALL has released an IPS signature to detect and block known exploits targeting this vulnerability. The following signature was released to address this issue:

• 1569 – RealNetworks RealPlayer QCP File Parsing Buffer Overflow