Cleartext storage of session identifier

User session identifiers were stored in cleartext - without processing of additional cryptographic hashing algorithms. This vulnerability cannot be exploited directly and occurs in combination with a chained attack - like for instance SQL injection in any other component of the system.

Solution

Update to TYPO3 versions 9.5.23 or 10.4.10 that fix the problem described.

Credits

Thanks to TYPO3 security team member Helmut Hummel who reported this issue and to TYPO3 core & security team members Benni Mack & Oliver Hader as well as TYPO3 contributor Markus Klein who fixed the issue.