CVE-2021-41113 is a high-severity (CVSS 8.8) Cross-Site Request Forgery (CSRF) vulnerability in typo3/cms-core. A fix is available for typo3/cms-core — see the affected versions and patch details below.
Cross-Site-Request-Forgery in Backend
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2021-41113 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
typo3/cms-core🐘typo3/cmsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Meta
- CVSS:
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C(8.2)
Problem
It has been discovered that the new TYPO3 v11 feature that allows users to create and share deep links in the backend user interface is vulnerable to cross-site-request-forgery.
The impact is the same as described in TYPO3-CORE-SA-2020-006 (CVE-2020-11069). However, it is not limited to the same site context and does not require the attacker to be authenticated. In a worst case scenario, the attacker could create a new admin user account to compromise the system.
To successfully carry out an attack, an attacker must trick his victim to access a compromised system. The victim must have an active session in the TYPO3 backend at that time.
The following Same-Site cookie settings in $GLOBALS[TYPO3_CONF_VARS][BE][cookieSameSite] are required for an attack to be successful:
- SameSite=strict: malicious evil.example.org invoking TYPO3 application at good.example.org
- SameSite=lax or none: malicious evil.com invoking TYPO3 application at example.org
Solution
Update your instance to TYPO3 version 11.5.0 which addresses the problem described.
Credits
Thanks to Richie Lee who reported this issue and to TYPO3 core & security team members Benni Mack and Oliver Hader who fixed the issue.
References
- TYPO3-CORE-SA-2021-014
- CVE-2020-11069 reintroduced in TYPO3 v11.2.0
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typo3/cms-core | ≥ 11.2.0&&< 11.5.0 | 11.5.0composer require typo3/cms-core:^11.5.0 |
| 🐘Packagist | typo3/cms | ≥ 11.2.0&&< 11.5.0 | 11.5.0composer require typo3/cms:^11.5.0 |
Affected Products
typo3typo3Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typo3/cms-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update typo3/cms-core to 11.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41113 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2021-41113 in your dependencies?
Find it across Packagist, including transitive dependencies.