CVE-2021-21340

Description

### Problem 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. ### Solution Update to TYPO3 versions 10.4.14, 11.1.1 that fix the problem described. ### Credits Thanks to Richie Lee who reported this issue and to TYPO3 framework merger Andreas Fernandez who fixed the issue. ### References * [TYPO3-CORE-SA-2021-007](https://typo3.org/security/advisory/typo3-core-sa-2021-007)

How to fix CVE-2021-21340

To remediate CVE-2021-21340, upgrade the affected package to a fixed version below.

• —upgrade to 10.4.14 or later
• —upgrade to 10.4.14 or later
• —upgrade to 10.4.14 or later
• —upgrade to 10.4.14 or later

Is CVE-2021-21340 being exploited?

Low — EPSS is 0.4%, meaning exploitation activity has not been observed at scale.

Affected packages (4)

• >= 10.0.0, < 10.4.14, >= 11.0.0, < 11.1.1
• >= 10.0.0, < 10.4.14
• >= 10.0.0, < 10.4.14
• >= 10.0.0, < 10.4.14

CVSS scores

References (6)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2021-21340
• WEBgithub.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-21340.yaml
• WEBgithub.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-21340.yaml
• WEBgithub.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-fjh3-g8gq-9q92