CVE-2021-41113

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

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

A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones. Typical impact: state-changing actions performed as the victim without their consent.

CVE-2021-41113 has a CVSS score of 8.8 (High). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (11.5.0); upgrading removes the vulnerable code path.

Kodem intelligence

Update your instance to TYPO3 version 11.5.0 which addresses the problem described.

1. What is CVE-2021-41113? CVE-2021-41113 is a high-severity cross-site request forgery (CSRF) vulnerability in typo3/cms-core (composer), affecting versions >= 11.2.0, < 11.5.0. It is fixed in 11.5.0. A victim's authenticated browser session is used to submit forged requests to an application that cannot distinguish them from legitimate ones.
2. How severe is CVE-2021-41113? CVE-2021-41113 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2021-41113?
   • typo3/cms-core (composer) (versions >= 11.2.0, < 11.5.0)
   • typo3/cms (composer) (versions >= 11.2.0, < 11.5.0)
4. Is there a fix for CVE-2021-41113? Yes. CVE-2021-41113 is fixed in 11.5.0. Upgrade to this version or later.
5. Is CVE-2021-41113 exploitable, and should I be worried? Whether CVE-2021-41113 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2021-41113 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2021-41113?
   • Upgrade typo3/cms-core to 11.5.0 or later
   • Upgrade typo3/cms to 11.5.0 or later