Date Discovered

June 6, 2007


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.

Technologies Affected

  • Yahoo! Messenger 8.0 2005.1.1.4
  • Yahoo! Messenger 8.0.0
  • Yahoo! Messenger
  • Yahoo! Messenger 8.0.1
  • Yahoo! Webcam ActiveX Control 2.0.1 .4


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.



Danny <server.exception@yahoo.com> and eEye Digital Security independently discovered this vulnerability.

© 1995- Symantec Corporation

Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.


The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.

Symantec, Symantec products, Symantec Security Response, and secure@symantec.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.