source: https://www.securityfocus.com/bid/11758/info

InMail and InShop are both reported susceptible to cross-site scripting vulnerabilities. These issues are due to a failure of the applications to properly sanitize user-supplied input prior to including it in dynamic Web pages.

These issues could permit a remote attacker to create a malicious URI link that includes hostile HTML and script code. If this link were to be followed, the hostile code may be rendered in the web browser of the victim user. This would occur in the security context of the affected web site and may allow for theft of cookie-based authentication credentials or other attacks.

http://www.example.com/mod_perl/inmail.pl?acao=<<h1>opss!</h1>
http://www.example.com/mod_perl/inshop.pl?screen=<script>alert(document.cookie);</script>