Yahoo! Messenger Webcam Viewer ActiveX control is prone to a buffer-overflow vulnerability because it fails to perform adequate boundary checks on user-supplied data. Successfully exploiting this issue allows remote attackers to execute arbitrary code in the context of applications that use the affected control (typically Internet Explorer). Yahoo! Messenger 8.0.1 is considered vulnerable; other versions may also be affected. DeepSight has identified this issue as being actively exploited in the wild in at least one website. The 'n.88tw.net' website is known to be hosting an exploit for this issue.
Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to requests that include NOP sleds and unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.
Do not follow links provided by unknown or untrusted sources.
To reduce the likelihood of successful attacks, never follow links provided by unknown or untrusted individuals.
Implement multiple redundant layers of security.
Various memory-protection schemes (such as nonexecutable and randomly mapped memory segments) may hinder an attacker's ability to exploit this vulnerability to execute arbitrary code.
Review and adjust according to policy any default configuration settings.
To mitigate the possibility of an exploit through HTML email, configure email clients to render messages in plain text. This mitigation may adversely affect some functionality of email clients.
The vendor has released an update to address this issue. Contact the vendor for details on obtianing the appropriate updates.