RealNetworks Helix Universal Server 9 media servers contain a buffer overflow in a RTSP protocol parser. Earlier versions of their media servers are also affected: RealSystem Server 7, 8, and RealServer G2.
RealNetworks Helix Universal Server 9 media server is software which provides integrated distribution of various forms of digital content. Streaming media content can include files encoded in QuickTime and MPEG formats. Helix Universal Server 9 uses a dynamic, shared library plug-in architecture to extend its functionality and support such RTP-delivered formats. Two of the plug-ins installed by default can be used to exploit a heap-based buffer overflow in a RTSP protocol parser. They are View Source plug-ins vsrcplin.so on UNIX platforms (vsrcplin.so.9.0 for Helix Universal Server, vsrcplin.so.6.0 for RealSystem Server 7, 8, and RealServer G2) and vsrc3260.dll on Windows systems. RealNetworks has published a statement recommending these two plug-ins be removed from the Plugins sub-directory in order to prevent this vulnerability from being exploited.
Previous versions of the RealNetworks streaming media server, including RealSystem Server 7, 8, and RealServer G2, are also vulnerable. The RealNetworks Helix Universal Proxy is reported not to be vulnerable.
A remote attacker can either execute arbitrary code with privileges of the running service or cause it to crash.
The CERT/CC is currently unaware of a definitive patch for this problem.
RealNetworks has posted the following response to this issue:
In summary, sites running vulnerable RealNetworks media servers should consider removing one of the following View Source plug-ins from the appropriate Plugins sub-directory: vsrcplin.so (vsrcplin.so.6.0 or vsrcplin.so.9.0) on UNIX platforms, vsrc3260.dll on Windows systems. Note the media server process must be restarted in order for this change to take affect. According to RealNetworks, this change will only disable the Content Browsing feature when implemented.
Affected sites could also block relevant RTSP service ports, which may include, but is not limited to, the following:
rtsp 554/tcp # Real Time Stream Control Protocol
rtsp 554/udp # Real Time Stream Control Protocol
arcp 7070/tcp # ARCP [legacy RealServer port]
arcp 7070/udp # ARCP [legacy RealServer port]
rtsp-alt 8554/tcp # RTSP Alternate (see port 554)
rtsp-alt 8554/udp # RTSP Alternate (see port 554)
This vulnerability is reported to have been discovered by Dave Aitel of Immunitysec.
This document was written by Jeffrey S Havrilla.
|Date First Published:||2003-08-29|
|Date Last Updated:||2003-09-09 20:45 UTC|