Yahoo! Messenger Webcam Upload 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 crash applications that use the affected control (typically Internet Explorer). Remote code execution may also be possible, but has not been confirmed. Yahoo! Messenger 8.0.1 is vulnerable; other versions may also be affected.
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 obtaining the appropriate updates.