CVE-2021-21339

Name: CVE-2021-21339
Creator: NVD / NIST
Published: 2021-03-23T02:15:12.453+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.92%

Last modified Jun 17, 2026

CVE-2021-21339 is a high-severity vulnerability rated 7.5/10 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 user session identifiers were stored in cleartext - without processing of additional cryptographic hashing algorithms. EPSS estimates a 0.92% 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 user session identifiers were stored in cleartext - without processing of additional cryptographic hashing algorithms. This vulnerability cannot be exploited directly and occurs in combination with a chained attack - like for instance SQL injection in any other component of the system. 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

7.5/10

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

EPSS Probability

0.92%

55.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-312

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-qx3w-4864-94chThird Party Advisory
https://packagist.org/packages/typo3/cms-coreRelease Notes, Third Party Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-006Vendor Advisory
https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-qx3w-4864-94chThird Party Advisory
https://packagist.org/packages/typo3/cms-coreRelease Notes, Third Party Advisory
https://typo3.org/security/advisory/typo3-core-sa-2021-006Vendor Advisory

Timeline

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

Frequently Asked Questions

What is CVE-2021-21339?

How severe is CVE-2021-21339?

CVE-2021-21339 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.92% probability of exploitation in the next 30 days.

How do I fix CVE-2021-21339?

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-2021-21339?

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

Scan your code now

Source: NVD / NIST