Problem Description

Failing to properly encode error messages, the components QueryGenerator and QueryView are vulnerable to both reflected and persistent cross-site scripting. A valid backend user account having administrator privileges is needed to exploit this vulnerability.

Solution

Update to TYPO3 versions 8.7.41 ELTS, 9.5.28, 10.4.18, 11.3.1 that fix the problem described.

Credits

Thanks to Richie Lee who reported this issue and to 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.