TYPO3-CORE-SA-2020-005: Insecure Deserialization in Backend User Settings

Categories: Development Created by Oliver Hader
It has been discovered that TYPO3 CMS is vulnerable to insecure deserialization.

Problem Description

It has been discovered that backend user settings (in $BE_USER->uc) are vulnerable to insecure deserialization. In combination with vulnerabilities of 3rd party components this can lead to remote code execution. A valid backend user account is needed to exploit this vulnerability.


Update to TYPO3 versions 9.5.17 or 10.4.2 that fix the problem described.


Thanks to TYPO3 security team member Oliver Hader who reported and fixed the issue.

General Advice

Follow the recommendations that are given in the TYPO3 Security Guide. Please subscribe to the typo3-announce mailing list.

General Note

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