TYPO3 vulnerable to Cross-Site Scripting in the ShowImageController

Problem

Failing to properly encode user-controlled values in file entities, the ShowImageController (eID tx_cms_showpic) is vulnerable to cross-site scripting. Exploiting this vulnerability requires a valid backend user account with access to file entities.

Solution

Update to TYPO3 versions 9.5.48 ELTS, 10.4.45 ELTS, 11.5.37 LTS, 12.4.15 LTS, 13.1.1 that fix the problem described.

Credits

Thanks to TYPO3 security team member Torben Hansen who reported this issue and to TYPO3 core & security team member Oliver Hader who fixed the issue.

References

• TYPO3-CORE-SA-2024-009