Revision History
None

Risk Impact
Medium

Malicious scripts hidden in URLs can be executed.

Overview
A vulnerability has been discovered in Symantec Web Security. Symantec Web Security fails to check and parse HTML tags in URLs included in error or block page messages displayed to the client, in the event of a blocked page.

An attacker can potentially include malicious scripts in the URL, which the client executes in the context of the site specified in the URL, in the event that the page is blocked.

Affected Components
Symantec Web Security 2.5, 3.0.0, and 3.0.1

Symantec Response
Symantec verified that this vulnerability exists in the currently supported versions of Symantec Web Security 3.0.1. This issue is fixed in the latest release of Symantec Web Security 3.0.1, build 62.

Mitigating Circumstances
The Symantec Web Security default block pages can be modified to not return the offending URL to the client.

Credit
Symantec takes the security and proper functionality of its products seriously. Symantec appreciates the efforts of Oliver.Karow and Brian Soby of Raytheon who independently discovered this vulnerability. Their assistance in the resolution of this vulnerability was indispensable.

Symantec takes the security and proper functionality of its products very seriously. As founding members of the Organization for Internet Safety (OISafety), Symantec follows the principles of responsible disclosure. Symantec also subscribes to the vulnerability guidelines outlined by the National Infrastructure Advisory Council (NIAC). Please contact secure@symantec.com if you feel you have discovered a potential or actual security issue with a Symantec product. A Symantec Product Security team member will contact you regarding your submission.

Symantec has developed a Product Vulnerability Handling Process document outlining the process we follow in addressing suspected vulnerabilities in our products. We support responsible disclosure of all vulnerability information in a timely manner to protect Symantec customers and the security of the Internet as a result of vulnerability. This document is available from the location provided below.

Symantec strongly recommends using encrypted email for reporting vulnerability information to secure@symantec.com. The Symantec Product Security PGP key can be obtained from the location provided below.

Symantec Vulnerability Response Policy

Symantec Product Vulnerability Management PGP Key

Copyright (c) 2008 by Symantec Corp.
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.

Disclaimer
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.

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