What is CVE-2021-21340?

CVE-2021-21340 is a medium-severity vulnerability in Typo3, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-03-23.

How severe is CVE-2021-21340?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Typo3

CVE-2021-21340

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 10.4.14, 11.1.1 it has been discovered that database fields used as _descriptionColumn_ are vulnerable to cross-site scripting when their content gets previewed. A valid backend user account is needed to exploit this vulnerability. This is fixed in versions 10.4.14, 11.1.1 .

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.009 (55.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Typo3
Typo3 Typo3.cms — versions >= 10.0.0, <= 10.4.13, >= 11.0.0, <= 11.1.0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
security-advisories@github.com (x_refsource_MISC, Vendor Advisory)

Frequently asked questions

What is CVE-2021-21340?: CVE-2021-21340 is a medium-severity vulnerability in Typo3, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-03-23.
How severe is CVE-2021-21340?: Medium severity. CVSS v3 base score is 5.4 out of 10.