Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
TYPO3 is an open source PHP based web content management system released under the GNU GPL. It has been discovered that the `FileDumpController` (backend and frontend context) is vulnerable to cross-site scripting when malicious files are displayed using this component. A valid backend user account is needed to exploit this vulnerability. This issue affects typo3/cms and typo3/cms-core versions 6.x, 7.0.x prior to 7.6.58, 8.0.x prior to 8.7.48, 9.0.x prior to 9.5.37, 10.0.x prior to 10.4.32, and 11.0.x prior to 11.5.16. There are no known workarounds for this issue.
CWE-79 - Cross Site Scripting
Cross-Site Scripting, commonly referred to as XSS, is the most dominant class of vulnerabilities. It allows an attacker to inject malicious code into a pregnable web application and victimize its users. The exploitation of such a weakness can cause severe issues such as account takeover, and sensitive data exfiltration. Because of the prevalence of XSS vulnerabilities and their high rate of exploitation, it has remained in the OWASP top 10 vulnerabilities for years.