GHSA-657m-v5vm-f6rw

Cross-Site-Request-Forgery in Backend

> ### 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](https://typo3.org/article/typo3-version-112-escape-the-orbit#c12178) is vulnerable to cross-site-request-forgery. The impact is the same as described in [TYPO3-CORE-SA-2020-006 (CVE-2020-11069)](https://typo3.org/security/advisory/typo3-core-sa-2020-006). 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](https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/8.7.x/Feature-90351-ConfigureTYPO3-shippedCookiesWithSameSiteFlag.html) 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](https://typo3.org/security/advisory/typo3-core-sa-2021-014) * [CVE-2020-11069](https://nvd.nist.gov/vuln/detail/CVE-2020-11069) reintroduced in TYPO3 v11.2.0