Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
TYPO3 is an open source PHP based web content management system. Typo3/cms and Typo3/cms-core versions 9.2.0 prior to 9.5.31, 10.3.0 prior to 10.4.33, 11.x prior to 11.5.20 and 12.x prior to 12.1.1 are subject to Sensitive Information Disclosure. Due to the lack of handling user-submitted YAML placeholder expressions in the site configuration backend module, attackers could expose sensitive internal information, such as system configuration or HTTP request messages of other website visitors. A valid backend user account having administrator privileges is needed to exploit this vulnerability.
CWE-917 - Improper Neutralization of Special Elements used in an Expression Language Statement ('Expression Language Injection')
The software constructs all or part of an expression language (EL) statement in a framework such as a Java Server Page (JSP) using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended EL statement before it is executed.