Uncontrolled Recursion

Summary

TYPO3 is an open source PHP based web content management system. In TYPO3 versions 9.2.0 through 9.5.31, 10.0.0 through 10.4.32 and 11.0.0 through 11.5.19 , requesting invalid or non-existing resources via HTTP triggers the page error handler, which again could retrieve content to be shown as an error message from another page. This leads to a scenario in which the application is calling itself recursively - amplifying the impact of the initial attack until the limits of the web server are exceeded. This vulnerability is very similar, but not identical, to the one described in CVE-2021-21359. This vulnerability also affects typo3/cms-core versions 9.3.0 through 9.5.31, 10.0.0 through 10.4.32 and 11.0.0 through 11.5.19 and typo3/cms-frontend versions v9.2.0 and 9.2.1.