A zero-day vulnerability has been disclosed within a RealPlayer ActiveX control (ierpplug.dll). By passing in malicious parameters into this ActiveX control, an attacker would be able to leverage a buffer overflow vulnerability within the control to execute arbitrary code under the context of the logged in user. Although exploit code has not been released for this vulnerability, exploits have been seen in-the-wild.
BeyondTrust Prevention and Detection:
BeyondTrust's Blink® Personal Edition protects from this vulnerability.
BeyondTrust's Blink® Professional Edition protects from this vulnerability.
BeyondTrust's Retina® Network Security Scanner scans devices to detect for this vulnerability.
Vendor Advisory: RealPlayer Security Vulnerability
The best form of mitigation is available by kill-bitting the CLSID for the ierpplug.dll ActiveX Control (FDC7A535-4070-4B92-A0EA-D9994BCC0DC5) following the directions of KB240797. This will disable calls to the ActiveX control from web pages, thereby mitigating these specific vulnerabilities.
Links:Original Vulnerability Information Released
Preview Vulnerability In Same ActiveX