This vulnerability allows remote attackers to execute arbitrary code on vulnerable installations of RealNetworks RealPlayer. User interaction is required to exploit this vulnerability in that the target must visit a malicious page.
The specific flaw exists within the RealPlayer ActiveX control. This module is responsible for handling the tfile, pnmm, cdda, protocol handlers. While parsing a long argument ending with ".smil" an attacker can overflow a buffer on the heap. This can be abused to execute arbitrary code under the context of the user invoking the control.