CVE-2021-21339: Cleartext storage of session identifier

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-03-23 · updated 2026-06-17
Weakness: CWE-312

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.

Affected products

typo3: from 6.2.0 before 6.2.57; from 7.0.0 before 7.6.51; from 8.0.0 before 8.7.40; from 9.0.0 before 9.5.25; from 10.0.0 before 10.4.14; from 11.0.0 before 11.1.1 — fixed in 10.4.14, 11.1.1, 6.2.57, 7.6.51, 8.7.40, 9.5.25

How to fix

Upgrade to a fixed version: typo3 10.4.14, 11.1.1, 6.2.57, 7.6.51. Check the vendor advisory for mitigations.

References

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