CVE-2020-11066: Improperly Controlled Modification of Dynamically-Determined Object Attributes in TYPO3 CMS

Severity: critical (CVSS 10.0 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-05-14 · updated 2026-06-17
Weakness: CWE-915

Description

In TYPO3 CMS greater than or equal to 9.0.0 and less than 9.5.17 and greater than or equal to 10.0.0 and less than 10.4.2, calling unserialize() on malicious user-submitted content can lead to modification of dynamically-determined object attributes and result in triggering deletion of an arbitrary directory in the file system, if it is writable for the web server. It can also trigger message submission via email using the identity of the web site (mail relay). Another insecure deserialization vulnerability is required to actually exploit mentioned aspects. This has been fixed in 9.5.17 and 10.4.2.

Affected products

typo3: from 9.0.0 before 9.5.17; from 10.0.0 before 10.4.2 — fixed in 10.4.2, 9.5.17

How to fix

Upgrade to a fixed version: typo3 10.4.2, 9.5.17. Check the vendor advisory for mitigations.

References

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