Typo3 » Typo3 : Security Vulnerabilities, CVEs, Published In 2020 (XSS) CVSS score >= 3

TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 9.5.23 and 10.4.10 the system extension Fluid (typo3/cms-fluid) of the TYPO3 core is vulnerable to cross-site scripting passing user-controlled data as argument to Fluid view helpers. Update to TYPO3 versions 9.5.23 or 10.4.10 that fix the problem described.

TYPO3 Fluid Engine (package `typo3fluid/fluid`) before versions 2.0.5, 2.1.4, 2.2.1, 2.3.5, 2.4.1, 2.5.5 or 2.6.1 is vulnerable to cross-site scripting when making use of the ternary conditional operator in templates like `{showFullName ? fullName : defaultValue}`. Updated versions of this package are bundled in following TYPO3 (`typo3/cms-core`) versions as well: TYPO3 v8.7.25 (using `typo3fluid/fluid` v2.5.4) and TYPO3 v9.5.6 (using `typo3fluid/fluid` v2.6.1).

In TYPO3 CMS 9.0.0 through 9.5.16 and 10.0.0 through 10.4.1, it has been discovered that the backend user interface and install tool are vulnerable to a same-site request forgery. A backend user can be tricked into interacting with a malicious resource an attacker previously managed to upload to the web server. Scripts are then executed with the privileges of the victims' user session. In a worst-case scenario, new admin users can be created which can directly be used by an attacker. The vulnerability is basically a cross-site request forgery (CSRF) triggered by a cross-site scripting vulnerability (XSS) - but happens on the same target host - thus, it's actually a same-site request forgery. Malicious payload such as HTML containing JavaScript might be provided by either an authenticated backend user or by a non-authenticated user using a third party extension, e.g. file upload in a contact form with knowing the target location. To be successful, the attacked victim requires an active and valid backend or install tool user session at the time of the attack. This has been fixed in 9.5.17 and 10.4.2. The deployment of additional mitigation techniques is suggested as described below. - Sudo Mode Extension This TYPO3 extension intercepts modifications to security relevant database tables, e.g. those storing user accounts or storages of the file abstraction layer. Modifications need to confirmed again by the acting user providing their password again. This technique is known as sudo mode. This way, unintended actions happening in the background can be mitigated. - https://github.com/FriendsOfTYPO3/sudo-mode - https://extensions.typo3.org/extension/sudo_mode - Content Security Policy Content Security Policies tell (modern) browsers how resources served a particular site are handled. It is also possible to disallow script executions for specific locations. In a TYPO3 context, it is suggested to disallow direct script execution at least for locations /fileadmin/ and /uploads/.

In TYPO3 CMS greater than or equal to 9.5.12 and less than 9.5.17, and greater than or equal to 10.2.0 and less than 10.4.2, it has been discovered that link tags generated by typolink functionality are vulnerable to cross-site scripting; properties being assigned as HTML attributes have not been parsed correctly. This has been fixed in 9.5.17 and 10.4.2.

In TYPO3 CMS greater than or equal to 9.0.0 and less than 9.5.17 and greater than or equal to 10.0.0 and less than 10.4.2, it has been discovered that HTML placeholder attributes containing data of other database records are vulnerable to cross-site scripting. A valid backend user account is needed to exploit this vulnerability. This has been fixed in 9.5.17 and 10.4.2.

svg.swf in TYPO3 6.2.0 to 6.2.38 ELTS and 7.0.0 to 7.1.0 could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack on a targeted system. This may be at a contrib/websvg/svg.swf pathname.