Backend users with write access to the form_definition database table were able to directly create, update, or delete form definition records via DataHandler, bypassing the Form Framework's persistence validation and permission checks. This allowed injecting arbitrary form configurations, re-enabling attack vectors originally addressed in TYPO3-CORE-SA-2018-003, including SQL injection and privilege escalation. This issue affects TYPO3 CMS versions 14.0.0-14.3.2.