CVE-2021-41114: HTTP Host Header Injection in Request Handling in Typo3
Meta CVSS: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:F/RL:O/RC:C (3.5)
Problem 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['TYPO3CONFVARS']['SYS']['trustedHostsPattern'] (used as an effective mitigation strategy in previous TYPO3 versions) was not evaluated anymore, and reintroduced the vulnerability.
Solution Update your instance to TYPO3 version 11.5.0 which addresses the problem described.
Credits Thanks to TYPO3 framework merger Benjamin Franzke who reported and fixed the issue.
References TYPO3-CORE-SA-2021-015 CVE-2014-3941 reintroduced in TYPO3 v11.0.0
Other sources
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['TYPO3CONFVARS']['SYS']['trustedHostsPattern'] (used as an effective mitigation strategy in previous TYPO3 versions) was not evaluated anymore, and reintroduced the vulnerability.
TYPO3-CORE-SA-2021-015: HTTP Host Header Injection in Request Handling
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
composer/typo3/cmsto a version that resolves this vulnerability.Fixed in 11.5.0 - Upgrade
Upgrade
composer/typo3/cms-coreto a version that resolves this vulnerability.Fixed in 11.5.0 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 11.5.0Patch TYPO3-CORE-SA-2021-015
Event History
Frequently Asked Questions
What is CVE-2021-41114?
CVE-2021-41114 is a vulnerability in TYPO3 CMS that allows host spoofing due to improper validation of the HTTP Host header.
What is the severity of CVE-2021-41114?
The severity of CVE-2021-41114 is medium, with a severity value of 5.3.
How does CVE-2021-41114 affect TYPO3 CMS?
CVE-2021-41114 affects TYPO3 CMS versions 11.0.0 to 11.5.0, allowing host spoofing.
How can I fix CVE-2021-41114?
To fix CVE-2021-41114, update TYPO3 CMS to a version higher than 11.5.0 and ensure proper validation of the HTTP Host header.
Are there any references for CVE-2021-41114?
Yes, you can find references for CVE-2021-41114 at the following links: [TYPO3 Security Advisory](https://typo3.org/security/advisory/typo3-core-sa-2021-015), [TYPO3 Commit](https://github.com/TYPO3/typo3/commit/5cbff85506cebe343e5ae59228977547cf8e3cf4), [TYPO3 Security Advisories](https://github.com/TYPO3/typo3/security/advisories/GHSA-m2jh-fxw4-gphm).