Headline
GHSA-744g-7qm9-hjh9: The TYPO3 CMS Backend has Broken Authentication in Backend MFA
Problem
The multifactor authentication (MFA) dialog presented during backend login can be bypassed due to insufficient enforcement of access restrictions on all backend routes.
Successful exploitation requires valid backend user credentials, as MFA can only be bypassed after successful authentication.
Solution
Update to TYPO3 versions 12.4.31 LTS, 13.4.12 LTS that fix the problem described.
Credits
Thanks to Jens Jacobsen and Y. Kahveci for reporting this issue, and to TYPO3 security team member Torben Hansen for fixing it.
Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.