TYPO3 Cross-Site Request Forgery in Backend User Module

Problem

A vulnerability has been identified in the backend user interface functionality involving deep links. Specifically, this functionality is susceptible to Cross-Site Request Forgery (CSRF). Additionally, state-changing actions in downstream components incorrectly accepted submissions via HTTP GET and did not enforce the appropriate HTTP method.

Successful exploitation of this vulnerability requires the victim to have an active session on the backend user interface and to be deceived into interacting with a malicious URL targeting the backend, which can occur under the following conditions:

• the user opens a malicious link, such as one sent via email.
• the user visits a compromised or manipulated website while the following settings are misconfigured: + security.backend.enforceReferrer feature is disabled, + BE/cookieSameSite configuration is set to lax or none

The vulnerability in the affected downstream component “Backend User Module” allows attackers to initiate password resets for other backend users or to terminate their user sessions.

Solution

Update to TYPO3 versions 11.5.42 ELTS, 12.4.25 LTS, 13.4.3 LTS that fix the problem described.

Credits

Thanks to Gabriel Dimitrov who reported this issue and to TYPO3 core and security members Benjamin Franzke, Oliver Hader, Andreas Kienast, Torben Hansen, Elias Häußler who fixed the issue.