This indicates an attack attempt against a heap-based buffer-overflow vulnerability in Mplayer.
Mplayer is a movie player software that supports a wide range of formats. Multiple vulnerabilities are reported in it that may allow an attacker to execute arbitrary code on the vulnerable system. This is due to the application's failure to properly check the bounds of streaming MMS/TCP data and RealMedia RTSP data. An attacker may send specially crafted streaming MMS/TCP data through a media server to cause a buffer overflow in MPlayer. A successful exploit could lead to arbitrary code execution.
MPlayer 1.0 pre6 and earlier versions
Compromise of the affected system.
Upgrade to Mplayer 1.0pre7 and later versions.