source: https://www.securityfocus.com/bid/15433/info

Pearl Forums is prone to a local file include vulnerability. This issue is due to a failure in the application to properly sanitize user-supplied input.

An attacker may leverage this issue to disclose sensitive information. This may help with further attacks on the affected computer.

It should be noted that this issue may also be leveraged to read arbitrary files on an affected computer with the privileges of the Web server.

http://www.example.com/support/index.php?mode=../../index