CVE-2026-33308

{"id": "CVE-2026-33308", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 6.8, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 4.0, "exploitabilityScore": 2.2}, {"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 2.2}]}, "published": "2026-03-24T03:16:06.080", "references": [{"url": "https://github.com/airtower-luna/mod_gnutls/security/advisories/GHSA-hm2g-m958-8qgh", "tags": ["Mitigation", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-295"}]}], "descriptions": [{"lang": "en", "value": "Mod_gnutls is a TLS module for Apache HTTPD based on GnuTLS. Prior to version 0.13.0, code for client certificate verification did not check the key purpose as set in the Extended Key Usage extension. An attacker with access to the private key for a valid certificate issued by a CA trusted for TLS client authentication but designated for a different purpose could have used that certificate to improperly access resources requiring TLS client authentication. Server configurations that do not use client certificates (`GnuTLSClientVerify ignore`, the default) are not affected. The problem has been fixed in version 0.13.0 by rewriting certificate verification to use `gnutls_certificate_verify_peers()`, and requiring key purpose id-kp-clientAuth (also known as `tls_www_client` in GnuTLS) by default if the Extended Key Usage extension is present. The new `GnuTLSClientKeyPurpose` option allows overriding the expected key purpose if needed (please see the manual for details). Behavior for certificates without an Extended Key Usage extension is unchanged. If dedicated (sub-)CAs are used for issuing TLS client certificates only (not for any other purposes) the issue has no practical impact."}, {"lang": "es", "value": "Mod_gnutls es un m\u00f3dulo TLS para Apache HTTPD basado en GnuTLS. Antes de la versi\u00f3n 0.13.0, el c\u00f3digo para la verificaci\u00f3n de certificados de cliente no verificaba el prop\u00f3sito de la clave tal como se establece en la extensi\u00f3n de Uso Extendido de Clave. Un atacante con acceso a la clave privada de un certificado v\u00e1lido emitido por una CA de confianza para la autenticaci\u00f3n de cliente TLS pero designado para un prop\u00f3sito diferente podr\u00eda haber utilizado ese certificado para acceder indebidamente a recursos que requieren autenticaci\u00f3n de cliente TLS. Las configuraciones de servidor que no utilizan certificados de cliente ('GnuTLSClientVerify ignore', el valor predeterminado) no se ven afectadas. El problema se ha solucionado en la versi\u00f3n 0.13.0 reescribiendo la verificaci\u00f3n de certificados para usar 'gnutls_certificate_verify_peers()' y requiriendo el prop\u00f3sito de clave id-kp-clientAuth (tambi\u00e9n conocido como 'tls_www_client' en GnuTLS) por defecto si la extensi\u00f3n de Uso Extendido de Clave est\u00e1 presente. La nueva opci\u00f3n 'GnuTLSClientKeyPurpose' permite anular el prop\u00f3sito de clave esperado si es necesario (consulte el manual para m\u00e1s detalles). El comportamiento para certificados sin una extensi\u00f3n de Uso Extendido de Clave no ha cambiado. Si se utilizan CA (o sub-CA) dedicadas solo para emitir certificados de cliente TLS (no para ning\u00fan otro prop\u00f3sito), el problema no tiene impacto pr\u00e1ctico."}], "lastModified": "2026-03-24T19:28:16.217", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:mod_gnutls_project:mod_gnutls:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E476F8C2-BB73-4776-A192-67E20C9CE6EC", "versionEndExcluding": "0.13.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}