omnipresent has discovered some vulnerabilities in ASPScriptz Guest Book, which can be exploited by malicious people to conduct script insertion attacks.

Input passed to the "GBOOK_UNAME", "GBOOK_EMAIL", "GBOOK_CITY", "GBOOK_COU", "GBOOK_WWW", and "GBOOK_MESS" form field parameters in submit.asp is not properly sanitised before being used. This can be exploited to insert arbitrary HTML and script code, which will be executed in a user's browser session in context of an affected site when a malicious entry is viewed.

NOTE: The "GBOOK_MESS" parameter can be exploited via a "img" bbcode tag with a "javascript:" URI handler when viewed with the Microsoft Internet Explorer browser.

The vulnerabilities have been confirmed in version 2.0. Other versions may also be affected.

Solution
Edit the source code to ensure that input is properly sanitised.

Provided and/or discovered by
omnipresent

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://colander.altervista.org/advisory/ASzGB.txt

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