phpBB 2.0.23 includes the session ID in a request to modcp.php when the moderator or administrator closes a thread, which allows remote att…

phpBB 2.0.23 includes the session ID in a request to modcp.php when the moderator or administrator closes a thread, which allows remote attackers to hijack the session via a post in the thread containing a URL to a remotely hosted image, which might include the session ID in the Referer header.