Cross-Site Scripting in Form Engine

• Component Type: TYPO3 CMS
• Subcomponent: Form Engine (ext:backend)
• Release Date: May 12, 2020
• Vulnerability Type: Cross-Site Scripting
• Affected Versions: 9.0.0-9.5.16, 10.0.0-10.4.1
• Severity: Medium
• Suggested CVSS: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C
• References: CVE-2020-11064, CWE-79

Problem Description

It has been discovered that HTML placeholder attributes containing data of other database records are vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability.

Solution

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

Credits

Thanks to Florian Weiss who reported this issue and to TYPO3 active contributor Markus Klein who 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

All security related code changes are tagged so that you can easily look them up in our review system.