{"api_version":"1","generated_at":"2026-04-23T02:37:44+00:00","cve":"CVE-2022-21656","urls":{"html":"https://cve.report/CVE-2022-21656","api":"https://cve.report/api/cve/CVE-2022-21656.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2022-21656","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2022-21656"},"summary":{"title":"CVE-2022-21656","description":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted.","state":"PUBLIC","assigner":"security-advisories@github.com","published_at":"2022-02-22 23:15:00","updated_at":"2023-07-24 13:50:00"},"problem_types":["CWE-843"],"metrics":[],"references":[{"url":"https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e","name":"https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e","refsource":"MISC","tags":[],"title":"Specify type for matching Subject Alternative Name. (#18628) · envoyproxy/envoy@bb95af8 · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"200"},{"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2","name":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2","refsource":"CONFIRM","tags":[],"title":"X.509 subjectAltName matching (and nameConstraints) bypass · Advisory · envoyproxy/envoy · GitHub","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2022-21656","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2022-21656","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2022","cve_id":"21656","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"envoyproxy","cpe5":"envoy","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2022-21656","STATE":"PUBLIC","TITLE":"X.509 subjectAltName matching bypass in Envoy"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"envoy","version":{"version_data":[{"version_value":"< 1.20.2"}]}}]},"vendor_name":"envoyproxy"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Envoy is an open source edge and service proxy, designed for cloud-native applications. The default_validator.cc implementation used to implement the default certificate validation routines has a \"type confusion\" bug when processing subjectAltNames. This processing allows, for example, an rfc822Name or uniformResourceIndicator to be authenticated as a domain name. This confusion allows for the bypassing of nameConstraints, as processed by the underlying OpenSSL/BoringSSL implementation, exposing the possibility of impersonation of arbitrary servers. As a result Envoy will trust upstream certificates that should not be trusted."}]},"impact":{"cvss":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-295: Improper Certificate Validation"}]}]},"references":{"reference_data":[{"name":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2","refsource":"CONFIRM","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-c9g7-xwcv-pjx2"},{"name":"https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e","refsource":"MISC","url":"https://github.com/envoyproxy/envoy/commit/bb95af848c939cfe5b5ee33c5b1770558077e64e"}]},"source":{"advisory":"GHSA-c9g7-xwcv-pjx2","discovery":"UNKNOWN"}},"nvd":{"publishedDate":"2022-02-22 23:15:00","lastModifiedDate":"2023-07-24 13:50:00","problem_types":["CWE-843"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE","baseScore":5.9,"baseSeverity":"MEDIUM"},"exploitabilityScore":2.2,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:M/Au:N/C:P/I:P/A:N","accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"PARTIAL","integrityImpact":"PARTIAL","availabilityImpact":"NONE","baseScore":5.8},"severity":"MEDIUM","exploitabilityScore":8.6,"impactScore":4.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*","versionEndExcluding":"1.20.2","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2022","CveId":"21656","Ordinal":"221428","Title":"CVE-2022-21656","CVE":"CVE-2022-21656","Year":"2022"},"notes":[{"CveYear":"2022","CveId":"21656","Ordinal":"1","NoteData":"** RESERVED ** This candidate has been reserved by an organization or individual that will use it when announcing a new security problem. When the candidate has been publicized, the details for this candidate will be provided.","Type":"Description","Title":null}]}}}