{"id":"CVE-2021-32813","state":"PUBLISHED","title":"Drop Headers via Malicious Connection Header","description":"Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of them sets a request header, then sending a request with a certain Connection header will cause it to be removed before the request is sent. In this case, the backend does not see the request header. A patch is available in version 2.4.13. There are no known workarounds aside from upgrading.","publishedAt":"2021-08-03T22:50:11.000Z","updatedAt":"2024-08-03T23:33:55.883Z","severity":{"score":4.8,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["traefik traefik"],"affected":[{"vendor":"traefik","product":"traefik","versions":[{"version":"< 2.4.13","status":"affected"},{"version":"<= 1.7.30","status":"affected"}]}],"references":["https://github.com/traefik/traefik/security/advisories/GHSA-m697-4v8f-55qg","https://github.com/traefik/traefik/pull/8319/commits/cbaf86a93014a969b8accf39301932c17d0d73f9","https://github.com/traefik/traefik/releases/tag/v2.4.13"],"weaknesses":["CWE-913"],"ingestedAt":"2026-10-29T19:48:33.225Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/32xxx/CVE-2021-32813.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-32813","state":"PUBLISHED","datePublished":"2021-08-03T22:50:11.000Z","dateUpdated":"2024-08-03T23:33:55.883Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2021-05-12T00:00:00.000Z"},"containers":{"cna":{"title":"Drop Headers via Malicious Connection Header","descriptions":[{"lang":"en","value":"Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of them sets a request header, then sending a request with a certain Connection header will cause it to be removed before the request is sent. In this case, the backend does not see the request header. A patch is available in version 2.4.13. There are no known workarounds aside from upgrading."}],"affected":[{"vendor":"traefik","product":"traefik","versions":[{"version":"< 2.4.13","status":"affected"},{"version":"<= 1.7.30","status":"affected"}]}],"references":[{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-m697-4v8f-55qg","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/traefik/traefik/pull/8319/commits/cbaf86a93014a969b8accf39301932c17d0d73f9","tags":["x_refsource_MISC"]},{"url":"https://github.com/traefik/traefik/releases/tag/v2.4.13","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.8,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-913","description":"CWE-913: Improper Control of Dynamically-Managed Code Resources","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","dateUpdated":"2021-08-03T22:50:11.000Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa"},"source":{"advisory":"GHSA-m697-4v8f-55qg","discovery":"UNKNOWN"},"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2021-32813","STATE":"PUBLIC","TITLE":"Drop Headers via Malicious Connection Header"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"traefik","version":{"version_data":[{"version_value":"< 2.4.13"},{"version_value":"<= 1.7.30"}]}}]},"vendor_name":"traefik"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Traefik is an HTTP reverse proxy and load balancer. Prior to version 2.4.13, there exists a potential header vulnerability in Traefik's handling of the Connection header. Active exploitation of this issue is unlikely, as it requires that a removed header would lead to a privilege escalation, however, the Traefik team has addressed this issue to prevent any potential abuse. If one has a chain of Traefik middlewares, and one of them sets a request header, then sending a request with a certain Connection header will cause it to be removed before the request is sent. In this case, the backend does not see the request header. A patch is available in version 2.4.13. There are no known workarounds aside from upgrading."}]},"impact":{"cvss":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.8,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-913: Improper Control of Dynamically-Managed Code Resources"}]}]},"references":{"reference_data":[{"name":"https://github.com/traefik/traefik/security/advisories/GHSA-m697-4v8f-55qg","refsource":"CONFIRM","url":"https://github.com/traefik/traefik/security/advisories/GHSA-m697-4v8f-55qg"},{"name":"https://github.com/traefik/traefik/pull/8319/commits/cbaf86a93014a969b8accf39301932c17d0d73f9","refsource":"MISC","url":"https://github.com/traefik/traefik/pull/8319/commits/cbaf86a93014a969b8accf39301932c17d0d73f9"},{"name":"https://github.com/traefik/traefik/releases/tag/v2.4.13","refsource":"MISC","url":"https://github.com/traefik/traefik/releases/tag/v2.4.13"}]},"source":{"advisory":"GHSA-m697-4v8f-55qg","discovery":"UNKNOWN"}}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://github.com/traefik/traefik/security/advisories/GHSA-m697-4v8f-55qg","tags":["x_refsource_CONFIRM","x_transferred"]},{"url":"https://github.com/traefik/traefik/pull/8319/commits/cbaf86a93014a969b8accf39301932c17d0d73f9","tags":["x_refsource_MISC","x_transferred"]},{"url":"https://github.com/traefik/traefik/releases/tag/v2.4.13","tags":["x_refsource_MISC","x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-03T23:33:55.883Z"}}]}}}