Zero-Day Advisory

Fortinet Discovers RealPlayer MP4 File Parsing Memory Corruption Vulnerability


Fortinet's FortiGuard Labs has discovered a buffer overflow vulnerability in RealNetworks RealPlayer.
RealPlayer is a cross-platform media player app, developed by RealNetworks. The media player is compatible with numerous container file formats of the multimedia realm, including MP3, MP4, QuickTime File Format, Windows Media format, and the proprietary RealAudio and RealVideo formats. RealPlayer is also available for other operating systems.
A buffer overflow vulnerability has been discovered in RealPlayer. The vulnerability can be triggered by a specifically crafted MP4 file with the "Sample Size" member of a 'stsz' structure having an overly long size value. Successful exploitation of this vulnerability could grant an attacker remote code execution.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released Dec 12, 2016

Users should apply the solution provided by RealNetworks.

Additional Information

Fortinet reported the vulnerability to RealNetworks on Sep. 7.

RealNetworks confirmed the vulnerability on Oct. 10.

RealNetworks patched the vulnerability on Dec. 20.


This vulnerability was discovered by Chris Navarrete and Xiaopeng Zhang of Fortinet's FortiGuard Labs

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.