{"containers":{"cna":{"affected":[{"product":"envoy","vendor":"envoyproxy","versions":[{"status":"affected","version":"<= 1.18.2"}]}],"descriptions":[{"lang":"en","value":"Envoy is a cloud-native edge/middle/service proxy. Envoy does not decode escaped slash sequences `%2F` and `%5C` in HTTP URL paths in versions 1.18.2 and before. A remote attacker may craft a path with escaped slashes, e.g. `/something%2F..%2Fadmin`, to bypass access control, e.g. a block on `/admin`. A backend server could then decode slash sequences and normalize path and provide an attacker access beyond the scope provided for by the access control policy. ### Impact Escalation of Privileges when using RBAC or JWT filters with enforcement based on URL path. Users with back end servers that interpret `%2F` and `/` and `%5C` and `\\` interchangeably are impacted. ### Attack Vector URL paths containing escaped slash characters delivered by untrusted client. Patches in versions 1.18.3, 1.17.3, 1.16.4, 1.15.5 contain new path normalization option to decode escaped slash characters. As a workaround, if back end servers treat `%2F` and `/` and `%5C` and `\\` interchangeably and a URL path based access control is configured, one may reconfigure the back end server to not treat `%2F` and `/` and `%5C` and `\\` interchangeably."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.1,"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:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-22","description":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2021-06-07T11:25:20.000Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"tags":["x_refsource_CONFIRM"],"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf"}],"source":{"advisory":"GHSA-4987-27fx-x6cf","discovery":"UNKNOWN"},"title":"Bypass of path matching rules using escaped slash characters","x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"security-advisories@github.com","ID":"CVE-2021-29492","STATE":"PUBLIC","TITLE":"Bypass of path matching rules using escaped slash characters"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"envoy","version":{"version_data":[{"version_value":"<= 1.18.2"}]}}]},"vendor_name":"envoyproxy"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"Envoy is a cloud-native edge/middle/service proxy. Envoy does not decode escaped slash sequences `%2F` and `%5C` in HTTP URL paths in versions 1.18.2 and before. A remote attacker may craft a path with escaped slashes, e.g. `/something%2F..%2Fadmin`, to bypass access control, e.g. a block on `/admin`. A backend server could then decode slash sequences and normalize path and provide an attacker access beyond the scope provided for by the access control policy. ### Impact Escalation of Privileges when using RBAC or JWT filters with enforcement based on URL path. Users with back end servers that interpret `%2F` and `/` and `%5C` and `\\` interchangeably are impacted. ### Attack Vector URL paths containing escaped slash characters delivered by untrusted client. Patches in versions 1.18.3, 1.17.3, 1.16.4, 1.15.5 contain new path normalization option to decode escaped slash characters. As a workaround, if back end servers treat `%2F` and `/` and `%5C` and `\\` interchangeably and a URL path based access control is configured, one may reconfigure the back end server to not treat `%2F` and `/` and `%5C` and `\\` interchangeably."}]},"impact":{"cvss":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.1,"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:H","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"}]}]},"references":{"reference_data":[{"name":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf","refsource":"CONFIRM","url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf"}]},"source":{"advisory":"GHSA-4987-27fx-x6cf","discovery":"UNKNOWN"}}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-03T22:11:05.253Z"},"title":"CVE Program Container","references":[{"tags":["x_refsource_CONFIRM","x_transferred"],"url":"https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf"}]}]},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2021-29492","datePublished":"2021-05-28T21:00:24.000Z","dateReserved":"2021-03-30T00:00:00.000Z","dateUpdated":"2024-08-03T22:11:05.253Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.1"}