{"attribution":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","cve":{"id":"CVE-2021-33503","sourceIdentifier":"cve@mitre.org","published":"2021-06-29T11:15:07.847","lastModified":"2026-06-17T03:54:41.387","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect."},{"lang":"es","value":"Se ha detectado un problema en urllib3 versiones anteriores a 1.26.5. Cuando se proporciona una URL que contiene muchos caracteres @ en el componente authority, la expresión regular de autoridad muestra un retroceso catastrófico, causando una denegación de servicio si fue pasado una URL como parámetro o es redirigido a ella por medio de un redireccionamiento HTTP"}],"affected":[{"source":"cve@mitre.org","affectedData":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"cvssMetricV2":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P","baseScore":5.0,"accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL"},"baseSeverity":"MEDIUM","exploitabilityScore":10.0,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-400"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:python:urllib3:*:*:*:*:*:*:*:*","versionStartIncluding":"1.25.4","versionEndExcluding":"1.26.5","matchCriteriaId":"39285E88-6838-4253-AD93-2717B1A8D1BC"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*","matchCriteriaId":"E460AA51-FCDA-46B9-AE97-E6676AA5E194"},{"vulnerable":true,"criteria":"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*","matchCriteriaId":"A930E247-0B43-43CB-98FF-6CE7B8189835"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*","matchCriteriaId":"B095CC03-7077-4A58-AB25-CC5380CDCE5A"},{"vulnerable":true,"criteria":"cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*","matchCriteriaId":"82EA4BA7-C38B-4AF3-8914-9E3D089EBDD4"},{"vulnerable":true,"criteria":"cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*","matchCriteriaId":"B9C9BC66-FA5F-4774-9BDA-7AB88E2839C4"},{"vulnerable":true,"criteria":"cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*","matchCriteriaId":"7F69B9A5-F21B-4904-9F27-95C0F7A628E3"},{"vulnerable":true,"criteria":"cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*","matchCriteriaId":"D3E503FB-6279-4D4A-91D8-E237ECF9D2B0"}]}]}],"references":[{"url":"https://github.com/advisories/GHSA-q2q7-5pp4-w6pg","source":"cve@mitre.org","tags":["Third Party Advisory"]},{"url":"https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec","source":"cve@mitre.org","tags":["Patch","Third Party Advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/","source":"cve@mitre.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/","source":"cve@mitre.org"},{"url":"https://security.gentoo.org/glsa/202107-36","source":"cve@mitre.org","tags":["Third Party Advisory"]},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","source":"cve@mitre.org","tags":["Patch","Third Party Advisory"]},{"url":"https://github.com/advisories/GHSA-q2q7-5pp4-w6pg","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"]},{"url":"https://github.com/urllib3/urllib3/commit/2d4a3fee6de2fa45eb82169361918f759269b4ec","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch","Third Party Advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6SCV7ZNAHS3E6PBFLJGENCDRDRWRZZ6W/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FMUGWEAUYGGHTPPXT6YBD53WYXQGVV73/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.gentoo.org/glsa/202107-36","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Third Party Advisory"]},{"url":"https://www.oracle.com/security-alerts/cpuoct2021.html","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch","Third Party Advisory"]}]}}