CVE-2021-29492

{"id": "CVE-2021-29492", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 7.5, "accessVector": "NETWORK", "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "LOW", "availabilityImpact": "PARTIAL", "confidentialityImpact": "PARTIAL"}, "acInsufInfo": false, "impactScore": 6.4, "baseSeverity": "HIGH", "obtainAllPrivilege": false, "exploitabilityScore": 10.0, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.2}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 8.3, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 3.7, "exploitabilityScore": 3.9}]}, "published": "2021-05-28T21:15:08.670", "references": [{"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf", "tags": ["Mitigation", "Third Party Advisory"], "source": "security-advisories@github.com"}, {"url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-4987-27fx-x6cf", "tags": ["Mitigation", "Third Party Advisory"], "source": "af854a3a-2127-422b-91ae-364da2661108"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-22"}]}], "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."}, {"lang": "es", "value": "Envoy es un proxy de borde/medio/servicio nativo de la nube. Envoy no descifra las secuencias de barras diagonales escapadas `%2F` y `%5C` en las rutas URL HTTP en las versiones 1.18.2 y anteriores. Un atacante remoto puede crear una ruta con barras escapadas, por ejemplo `algo%2F..%2Fadmin`, para saltarse el control de acceso, por ejemplo, un bloqueo en `/admin`. Un servidor backend podr\u00eda entonces decodificar las secuencias de barras y normalizar la ruta y proporcionar a un atacante acceso m\u00e1s all\u00e1 del alcance previsto por la pol\u00edtica de control de acceso. ### Impacto Escalada de Privilegios cuando se utilizan filtros RBAC o JWT con aplicaci\u00f3n basada en la ruta de la URL. Los usuarios con servidores de back-end que interpretan `%2F` y `/` y `%5C` y `\\` indistintamente est\u00e1n impactados. ### Vector de ataque Rutas de URL que contienen caracteres de barra diagonal escapados entregados por un cliente que no es de confianza. Los parches de las versiones 1.18.3, 1.17.3, 1.16.4 y 1.15.5 contienen una nueva opci\u00f3n de normalizaci\u00f3n de rutas para descodificar los caracteres de barra diagonal escapados. Como soluci\u00f3n, si los servidores finales tratan `%2F` y `/` y `%5C` y `\\` indistintamente y se configura un control de acceso basado en la ruta de la URL, se puede reconfigurar el servidor final para que no trate `%2F` y `/` y `%5C` y `\\` indistintamente"}], "lastModified": "2024-11-21T06:01:14.917", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "EE9E311E-85FF-42AA-B0A3-C138D436932D", "versionEndExcluding": "1.15.5"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D36D66BB-9C95-4E59-AA78-6824ACCB89D7", "versionEndExcluding": "1.16.4", "versionStartIncluding": "1.16.0"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D502D5F9-38A7-46B1-890D-2A177B76AEBB", "versionEndExcluding": "1.17.3", "versionStartIncluding": "1.17.0"}, {"criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BA3D8EC7-7D60-41C5-9770-3521DB6F7650", "versionEndExcluding": "1.18.3", "versionStartIncluding": "1.18.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}