Secunia

Description
Two vulnerabilities have been identified in MPCSoftWeb Guest Book, which can be exploited by malicious people to conduct Cross-Site Scripting attacks against other users or retrieve information stored in the database.

User input supplied to the "Name", "Location", and "Comment" fields in "insertguest.asp" is not validated, which can be exploited by posting a malicious entry in the guestbook. Script code will be executed in the user's browser session, when the entry is viewed.

This can result in disclosure of various information (eg. cookie-based authentication information) associated with the site running MPCSoftWeb Guest Book or inclusion of malicious content, which the user thinks is part of the real website.

A malicious person can also download the database file, which stores the administrator password in clear text.

Example:
http://[victim]/mpcsoftweb_guestbook/database/mpcsoftweb_guestdata.mdb

Solution
Filter malicious characters in a HTTP proxy or firewall with URL filtering capabilities.
Further details available in Customer Area

Provided and/or discovered by
drG4njubas

Original Advisory
http://www.blacktigerz.org/filez/advisory011.txt

Deep Links
Links available in Customer Area