Component Type: Third party extensions. These extensions are not part of the TYPO3 default installation.
Affected Versions: All versions (1.4.0, 1.6.0, 2.2.1 to 2.2.7, 2.3.0 to 2.3.6, 2.4.0, 2.5.0 to 2.5.9)
Vulnerability Type: Cross Site Scripting, Remote Code Execution
Solution: Updated versions are available from the TYPO3 extension manager.
Users of TYPO3 3.x have to upgrade to extension version 2.2.8 which is also available at typo3.org/extensions/repository/view/sr_feuser_register/2.2.8/
Users of TYPO3 4.x have to upgrade to extension version 2.5.10 which is also available at typo3.org/extensions/repository/view/sr_feuser_register/2.5.10/
Credits: Credits go to Philipp Hoffmann, Martin Sonnek and Daniel PÃ¶tzinger, who discovered the issues. Furthermore the TYPO3 Security Team wishes to thank the extension author Franz Holzinger for fixing the issue.