Guestserver guestbook system vulnerabilities

[jaakko () ritke fi]

The poor security and input validation at Guestserver versions below 5 ( there are still lots of them out there ) allow 
all HTML tags inside a message and it can be exploited as much as you want to.

http://www.stud.ntnu.no/~larsell/guestserver/

A Google Search for "Guestbook by  Guestserver - v4.12" for example comes up with tons of vulnerable sites.