CVE-2022-36105 is a medium-severity vulnerability affecting TYPO3, an open-source PHP-based web content management system widely used for building and managing websites. The vulnerability arises from an observable discrepancy in response times during user authentication processes on both backend and frontend login attempts. Specifically, an attacker can measure the time taken by the system to respond to authentication requests and use this timing information to distinguish between existing and non-existing user accounts. This side-channel timing attack exploits the fact that TYPO3 processes valid and invalid usernames with different response times, leaking information about user account existence. This can facilitate further targeted attacks such as brute force password guessing, social engineering, or reconnaissance for privilege escalation. The vulnerability also affects third-party TYPO3 extensions that implement custom authentication services if they do not implement the new MimicServiceInterface::mimicAuthUser method, which simulates consistent processing times to mitigate timing discrepancies. The issue affects TYPO3 versions from 7.0.0 up to but not including 7.6.58, 8.0.0 up to 8.7.48, 9.0.0 up to 9.5.37, 10.0.0 up to 10.4.32, and 11.0.0 up to 11.5.16. The vulnerability was publicly disclosed on September 13, 2022, and fixed in the specified patched versions. No known exploits are currently observed in the wild, and no workarounds exist other than upgrading to patched versions or ensuring third-party extensions implement the timing mimic interface. The vulnerability is classified under CWE-203 (Observable Discrepancy), indicating a side-channel information leak through timing differences during authentication.

For European organizations using TYPO3 for their web content management, this vulnerability poses a moderate risk primarily related to information disclosure. Attackers can enumerate valid user accounts by measuring authentication response times, which can lead to targeted brute force attacks or social engineering campaigns. This undermines the confidentiality of user account information and can facilitate unauthorized access if combined with weak password policies or other vulnerabilities. While the vulnerability does not directly allow account takeover or code execution, it increases the attack surface and the likelihood of successful credential-based attacks. Organizations in sectors with sensitive data or critical infrastructure relying on TYPO3 may face increased risk of targeted attacks. Additionally, the lack of known exploits in the wild suggests limited immediate threat, but the vulnerability's presence in multiple TYPO3 versions means many organizations could be exposed if they have not applied patches. The impact on integrity and availability is low, but confidentiality leakage through user enumeration can have significant downstream consequences. European organizations with public-facing TYPO3 installations, especially government, healthcare, finance, and media sectors, should be particularly vigilant due to the potential for targeted reconnaissance by threat actors.

The primary mitigation is to upgrade TYPO3 installations to the fixed versions: 7.6.58 ELTS, 8.7.48 ELTS, 9.5.37 ELTS, 10.4.32, or 11.5.16 or later. Organizations should audit all third-party TYPO3 extensions that provide custom authentication services to ensure they implement the MimicServiceInterface::mimicAuthUser method, which standardizes authentication response times to prevent timing attacks. If upgrading immediately is not feasible, organizations should consider implementing web application firewall (WAF) rules to detect and block suspicious authentication timing probes, although this is a partial and less reliable mitigation. Monitoring authentication logs for unusual patterns of login attempts or timing-based reconnaissance can help detect exploitation attempts. Additionally, enforcing strong password policies and multi-factor authentication (MFA) can reduce the risk of account compromise even if user enumeration occurs. Regular security assessments and penetration testing focusing on authentication mechanisms are recommended to identify similar timing or side-channel vulnerabilities. Finally, organizations should maintain an inventory of TYPO3 versions in use and establish patch management processes to ensure timely updates.