ShineShadow Security Report 14082009-08 TITLE ICQ 6.5 HTML-injection vulnerability BACKGROUND With more than 700 million instant messages sent and received every day, ICQ has been known to the online community as a messaging service. Today, a little more than a decade after the first ICQ instant messaging service was launched it has become much more than just that. ICQ is a personal communication tool that allows users to meet and interact through instant messaging services such as text, voice, video and VoIP as well as various entertainment and community products. Source: http://www.icq.com VULNERABLE PRODUCTS ICQ 6.5 build 1042 (latest build) Previous versions and localized distributions may also be affected DETAILS HTML-injection vulnerability exists in official ICQ client software. Incoming message window in the vulnerable ICQ client has a web browser nature. An attacker can try to exploit the vulnerability by sending specially crafted message to the remote ICQ client. The malicious message can contain text data which will be interpreted and displayed in the incoming message window as a HTML code. Potentially an arbitrary HTML code could be injected. There are two impacts of the vulnerability has been detected: 1.Information disclosure For example, an attacker can inject tag that could lead information disclosure (such as remote client’s IP address, browser version, OS version, etc.) 2.Spoofing An attacker can spoof ICQ client software’s system messages, interface elements (buttons, links) in the message window, etc. For example, it could be used for forcing of the ICQ users to click on attacker’s malicious link. Maybe other impacts are possible. EXPLOITATION Remote attacker can exploit this vulnerability using any instant messenger software with OSCAR (ICQ) protocol support by sending specially crafted message. Example of exploit message: file://1">[HTML CODE] Notice that internal ICQ antispam engine will blocked some text/html data if attacker’s ICQ UIN not in user’s ICQ contact list. DISCLOSURE POLICY The “Full disclosure” policy has been applied. Vendor has not been contacted. CREDITS Maxim A. Kulakov (aka ShineShadow) ss_contacts@hotmail.com