source: https://www.securityfocus.com/bid/12647/info

OOApp Guestbook is reportedly affected by multiple HTML injection vulnerabilities. These issues occur because the application fails to properly sanitize user-supplied input.

The attacker-supplied HTML and script code would be able to access properties of the site, potentially allowing for theft of 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. 

http://www.example.com/home.php?do=del;id=%31%27%3E%0A[Javascript]%31%27%3E%0A = 1'>