GHSA-hww5-6x85-mc24 Typo3 Arbitrary Code Execution and Cross-Site Scripting in Backend API

• Packagist typo3/cms: >= 8.0.0, < 8.7.27 → fixed in 8.7.27 • Packagist typo3/cms: >= 9.0.0, < 9.5.8 → fixed in 9.5.8

Backend API configuration using Page TSconfig is vulnerable to arbitrary code execution and cross-site scripting. TSconfig fields of page properties in backend forms can be used to inject malicious sequences. Field tsconfig_includes is vulnerable to directory traversal leading to same scenarios as having direct access to TSconfig settings. A valid backend user account having access to modify values for fields pages.TSconfig and pages.tsconfig_includes is needed in order to exploit this vulnerability.