Check Point Advisories

Security Best Practice: Blocking Yahoo! Messenger

Check Point Reference:	SBP-2010-01
Date Published:	5 Jan 2010
Severity:	Medium
Last Updated:	Friday 01 January, 2010
Source:	IPS Research Center
Protection Provided by:
Who is Vulnerable?	Yahoo! Messenger users
Vulnerability Description	Instant Messaging applications allow communication and collaboration between Internet users using various modes of communication, including instant messages exchange, voice and video, application sharing, white board, file transfer and remote assistance. Yahoo! Messenger is an advertisement-supported instant messaging client and associated protocol provided by Yahoo!. In addition to instant messaging features, it also offers IMVironments, address-book integration and Custom Status Messages.
Vulnerability Details	Some organizations prefer to prevent their employees from using Instant Messaging applications, since many Instant Messaging applications are prone to multiple vulnerabilities. The impacts of these vulnerabilities could range from modifying data in a victim's friend list, to a denial of service attack, to the execution of malicious code on a victim's system. In addition, Instant Messaging capabilities such as file transfer are a potential source of virus and worm infections.