CVE-2021-21338

Name: CVE-2021-21338
Creator: NVD / NIST
Published: 2021-03-23T02:15:12.36+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 1.10%

Last modified Jun 17, 2026

CVE-2021-21338 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1 it has been discovered that Login Handling is susceptible to open redirection which allows attackers redirecting to arbitrary content, and conducting phishing attacks. EPSS estimates a 1.10% chance of exploitation in the next 30 days.

Description

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1 it has been discovered that Login Handling is susceptible to open redirection which allows attackers redirecting to arbitrary content, and conducting phishing attacks. No authentication is required in order to exploit this vulnerability. This is fixed in versions 6.2.57, 7.6.51, 8.7.40, 9.5.25, 10.4.14, 11.1.1.

Metrics

CVSS 3.1

6.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

EPSS Probability

1.10%

61.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Typo3	Typo3	>= 6.2.0, < 6.2.57
Typo3	Typo3	>= 7.0.0, < 7.6.51
Typo3	Typo3	>= 8.0.0, < 8.7.40
Typo3	Typo3	>= 9.0.0, < 9.5.25
Typo3	Typo3	>= 10.0.0, < 10.4.14
Typo3	Typo3	>= 11.0.0, < 11.1.1

References

https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmpThird Party Advisory
https://packagist.org/packages/typo3/cms-coreRelease Notes, Third Party Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-001Vendor Advisory
https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4jhw-2p6j-5wmpThird Party Advisory
https://packagist.org/packages/typo3/cms-coreRelease Notes, Third Party Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-001Vendor Advisory

Timeline

Published: Mar 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-21338?

How severe is CVE-2021-21338?

CVE-2021-21338 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 1.10% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21338?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-21338?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST