Problem Description

Admin Tool sessions initiated via the TYPO3 backend user interface have not been revoked even if the corresponding user account was degraded to lower permissions or disabled completely. This way, sessions in the admin tool theoretically could have been prolonged without any limit.

Solution

Update to TYPO3 versions 9.5.35 ELTS, 10.4.29, 11.5.11 that fix the problem described above.

Credits

Thanks to Kien Hoang who reported this issue and to TYPO3 framework merger Ralf Zimmermann and TYPO3 security team member Oliver Hader who fixed the issue.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.

General Note

All security related code changes are tagged so that you can easily look them up in our review system.