- Component Type: TYPO3 CMS
- Subcomponent: Content Preview Renderer (ext:backend)
- Release Date: March 16, 2021
- Vulnerability Type: Cross-Site Scripting
- Affected Versions: 10.0.0-10.4.1, 11.0.0-11.1.0
- 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-2021-21340, CWE-79
It has been discovered that database fields used as descriptionColumn are vulnerable to cross-site scripting when their content gets previewed in the page module. A valid backend user account is needed to exploit this vulnerability.
Update to TYPO3 versions 10.4.14, 11.1.1 that fix the problem described.
Thanks to Richie Lee who reported this issue and to TYPO3 framework merger Andreas Fernandez who fixed the issue.
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