Additional information is available for the Cisco Secure Desktop remote cross-site scripting vulnerability.
Cisco Secure Desktop contains a vulnerability that could allow an unauthenticated, remote attacker to conduct cross-site scripting attacks.
The vulnerability is due to a lack of input sanitation in the Cisco Secure Desktop. An unauthenticated, remote attacker could exploit this vulnerability by convincing a targeted user to visit a malicious website that is designed to submit an HTTP POST request to the web interface of the affected product. If the targeted user visits the malicious page, the attacker could execute arbitrary script code in the browser of the user in the security context of the affected site.
Proof-of-concept code is publicly available.
Cisco has confirmed this vulnerability and released updated software.
Cisco Secure Desktop versions prior to 3.5 are vulnerable. Cisco Secure Desktop is a component of Cisco ASA 5500 Series Adaptive Security Appliances. Cisco ASA appliances are vulnerable only if the Cisco Secure Desktop feature has been enabled. Cisco ASA appliance versions prior to 8.2(1), 8.1(2.7), and 8.0(5) are vulnerable.
To exploit this vulnerability, an attacker must convince a targeted user to visit a malicious website. Performing an exploit will likely require the attacker to use social engineering tactics, such as sending targeted users a link to the site via e-mail, instant messaging, or another form of communication.
Cisco would like to thank Matias Pablo Brutti and Ernesto Alvarez from Core Security Technologies for discovering this vulnerability.
Because of changes made in Cisco Secure Desktop 3.5, Cisco ASA with an older version of ASA firmware but with Cisco Secure Desktop 3.5 or later will not be affected by this vulnerability.
The problem is fixed for Cisco ASA firmware version 8.0(5) and later.
Cisco bug ID CSCsw15646 has been assigned to this vulnerability.
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary script code in the user's browser in the security context of the affected site. Code execution could allow the attacker to take actions as the user on that site or obtain recently submitted data.
The vulnerability is due to a lack of input sanitation in a POST variable that is used by binary/mainv.js and then evaluated without first sanitizing the input in the start.html web page. An unauthenticated, remote attacker could exploit this vulnerability by constructing a malicious web page that submits an HTTP POST request to the affected application. When the application returns a response, it may contain attacker-supplied script code that could execute in the targeted user's browser in the security context of the affected site.
Administrators are advised to apply the appropriate updates.
Users are advised not to open e-mail messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in e-mail messages are safe, they are advised not to open them.
The Cisco Applied Intelligence team has created the following companion document to guide administrators in identifying and mitigating attempts to exploit this vulnerability prior to applying updated software: cisco-amb-20060922-understanding-xss
Users should verify that unsolicited links are safe to follow.
Cisco has released the following fixed versions:
Cisco Secure Desktop Version 3.5
Cisco ASA 5500 Series Adaptive SecurityAppliances Versions 8.2(1), 8.1(2.7), and 8.0(5)
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via e-mail at firstname.lastname@example.org.
Version 3, February 5, 2010, 3:02 PM: This alert clarifies information that was reported in the initial CVSS score that proof-of-concept code is publicly available for the Cisco Secure Desktop remote cross-site scripting vulnerability.
Version 2, February 2, 2010, 9:23 AM: The Cisco Applied Mitigation Bulletin on cross-site scripting can help mitigate the Cisco Secure Desktop remote cross-site scripting vulnerability.
Version 1, February 1, 2010, 2:54 PM: Cisco Secure Desktop contains a vulnerability that could allow an unauthenticated, remote attacker to conduct cross-site scripting attacks. Updates are available.
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.