CVE-2021-41113

TYPO3 is an open source PHP based web content management system released
under the GNU GPL. 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 and SameSite=lax or none: malicious
evil.com invoking TYPO3 application at example.org. Update your instance to
TYPO3 version 11.5.0 which addresses the problem described.