chacmool Private Message System 1.1.3 - 'send.php' Arbitrary Message Access
source: https://www.securityfocus.com/bid/11671/info
Private Message System is reported prone to multiple vulnerabilities that can allow remote attackers to carry out cross-site scripting attacks and disclose arbitrary private messages.
Private Message System 1.1.3 is reported vulnerable to these issue, however, it is possible that other version are affected as well.
http://www.example.com/message_send.php?quote=[ID]