Component Type: Third party extension. This extension is not a part of the TYPO3 default installation.
Affected Versions: Version 1.9.0 and all versions below
Vulnerability Type: Information Disclosure
Release Date: 13.08.2010
Problem Description: The extension disloses PHP version number and IP addresses of (subscribed) website users. In detail, IP addresses of those users are exposed who send private messages to others or take part in forum discussions.
Solution: An updated version 1.9.1 is available from the TYPO3 extension manager and at typo3.org/extensions/repository/view/mm_forum/1.9.1/. Users of the extension are advised to update the extension as soon as possible.
Credits: Credits go to Steffen Gebert, who discovered and reported the issue.