TYPO3 before 4.1.14, 4.2.x before 4.2.13, 4.3.x before 4.3.4 and 4.4.x before 4.4.1 contains an insecure default value of the variable fileDenyPattern which could allow remote attackers to execute arbitrary code on the backend.
The page module in TYPO3 before 8.7.11, and 9.1.0, has XSS via $GLOBALS['TYPO3_CONF_VARS']['SYS']['sitename'], as demonstrated by an admin entering a crafted site name during the installation process.
Multiple cross-site scripting (XSS) vulnerabilities in TYPO3 CMS 4.1.x before 4.1.14, 4.2.x before 4.2.13, 4.3.x before 4.3.4, and 4.4.x before 4.4.1 allow remote authenticated backend users to inject arbitrary web script or HTML via unspecified parameters to the extension manager, or unspecified parameters to unknown backend forms.
Extbase in TYPO3 4.3.0 before 6.2.24, 7.x before 7.6.8, and 8.1.1 allows remote attackers to obtain sensitive information or possibly execute arbitrary code via a crafted Extbase action.