{"id":"CVE-2021-21359","aliases":["BIT-typo3-2021-21359","GHSA-4p9g-qgx9-397p"],"url":"https://o3.security/vulnerability/CVE-2021-21359","summary":"Denial of Service in Page Error Handling","details":"TYPO3 is an open source PHP based web content management system. In TYPO3 before versions 9.5.25, 10.4.14, 11.1.1 requesting invalid or non-existing resources via HTTP triggers the page error handler which again could retrieve content to be shown as 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 is fixed in versions 9.5.25, 10.4.14, 11.1.1.","published":"2021-03-23T02:15:12.893Z","modified":"2026-08-27T08:14:37.911329Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Packagist","name":"typo3/cms-core","fixedVersion":"10.4.14"},{"ecosystem":"Packagist","name":"typo3/cms-core","fixedVersion":"11.1.1"},{"ecosystem":"Packagist","name":"typo3/cms-core","fixedVersion":"9.5.25"},{"ecosystem":"Packagist","name":"typo3/cms","fixedVersion":"10.4.14"},{"ecosystem":"Packagist","name":"typo3/cms","fixedVersion":"11.1.1"},{"ecosystem":"Packagist","name":"typo3/cms","fixedVersion":"9.5.25"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-4p9g-qgx9-397p"},{"type":"ADVISORY","url":"https://packagist.org/packages/typo3/cms-core"},{"type":"ADVISORY","url":"https://typo3.org/security/advisory/typo3-core-sa-2021-005"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T08:14:37.911329Z"}}