CVE-2021-41114

HTTP Host Header Injection in Request Handling in Typo3

Description

TYPO3 is an open source PHP based web content management system released under the GNU GPL. It has been discovered that TYPO3 CMS is susceptible to host spoofing due to improper validation of the HTTP Host header. TYPO3 uses the HTTP Host header, for example, to generate absolute URLs during the frontend rendering process. Since the host header itself is provided by the client, it can be forged to any value, even in a name-based virtual hosts environment. This vulnerability is the same as described in TYPO3-CORE-SA-2014-001 (CVE-2014-3941). A regression, introduced during TYPO3 v11 development, led to this situation. The already existing setting $GLOBALS['TYPO3_CONF_VARS']['SYS']['trustedHostsPattern'] (used as an effective mitigation strategy in previous TYPO3 versions) was not evaluated anymore, and reintroduced the vulnerability.

Category

4.8
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.29%
Vendor Advisory typo3.org
Affected: TYPO3 typo3
Published at:
Updated at:

References

Link Tags
https://github.com/TYPO3/typo3/security/advisories/GHSA-m2jh-fxw4-gphm third party advisory
https://github.com/TYPO3/typo3/commit/5cbff85506cebe343e5ae59228977547cf8e3cf4 third party advisory patch
https://typo3.org/security/advisory/typo3-core-sa-2021-015 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-41114?
CVE-2021-41114 has been scored as a medium severity vulnerability.
How to fix CVE-2021-41114?
To fix CVE-2021-41114, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-41114 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-41114 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-41114?
CVE-2021-41114 affects TYPO3 typo3.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.