{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-06-26T11:18:40.807","vulnerabilities":[{"cve":{"id":"CVE-2021-3634","sourceIdentifier":"secalert@redhat.com","published":"2021-08-31T17:15:08.323","lastModified":"2026-06-17T04:05:28.780","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id. Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also change the key exchange method, which can be based on hash of different size, eventually creating \"secret_hash\" of different size than the session_id has. This becomes an issue when the session_id memory is zeroed or when it is used again during second key re-exchange."},{"lang":"es","value":"Se ha encontrado un fallo en libssh en versiones anteriores a 0.9.6. El protocolo SSH mantiene un registro de dos secretos compartidos durante el tiempo de la sesión. Uno de ellos se llama secret_hash y el otro session_id. Inicialmente, ambos son el mismo, pero después del recambio de claves, el session_id anterior es mantenida y usada como entrada para el nuevo secret_hash. Históricamente, ambos búferes tenían una variable de longitud compartida, que funcionaba mientras estos búferes eran iguales. Pero la operación de recambio de claves también puede cambiar el método de intercambio de claves, que puede ser basado en un hash de diferente tamaño, creando eventualmente \"secret_hash\" de diferente tamaño que el session_id presenta. Esto se convierte en un problema cuando la memoria de session_id se pone a cero o cuando es usada de nuevo durante el segundo intercambio de claves"}],"affected":[{"source":"secalert@redhat.com","affectedData":[{"vendor":"n/a","product":"libssh","versions":[{"version":"libssh 0.9.6","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":6.5,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":2.8,"impactScore":3.6}],"cvssMetricV2":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"2.0","vectorString":"AV:N/AC:L/Au:S/C:N/I:N/A:P","baseScore":4.0,"accessVector":"NETWORK","accessComplexity":"LOW","authentication":"SINGLE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL"},"baseSeverity":"MEDIUM","exploitabilityScore":8.0,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"weaknesses":[{"source":"secalert@redhat.com","type":"Secondary","description":[{"lang":"en","value":"CWE-787"}]},{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-787"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:libssh:libssh:*:*:*:*:*:*:*:*","versionStartIncluding":"0.9.1","versionEndExcluding":"0.9.6","matchCriteriaId":"45D76734-EC25-46B5-BA69-C3A6809CB194"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:*","matchCriteriaId":"6BBD7A51-0590-4DDF-8249-5AFA8D645CB6"},{"vulnerable":true,"criteria":"cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:-:*:*:*","matchCriteriaId":"053C1B35-3869-41C2-9551-044182DE0A64"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*","matchCriteriaId":"07B237A9-69A3-4A9C-9DA0-4E06BD37AE73"},{"vulnerable":true,"criteria":"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*","matchCriteriaId":"FA6FEEC2-9F11-4643-8827-749718254FED"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*","matchCriteriaId":"E460AA51-FCDA-46B9-AE97-E6676AA5E194"},{"vulnerable":true,"criteria":"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*","matchCriteriaId":"A930E247-0B43-43CB-98FF-6CE7B8189835"},{"vulnerable":true,"criteria":"cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*","matchCriteriaId":"80E516C0-98A4-4ADE-B69F-66A772E2BAAA"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:oracle:mysql_workbench:*:*:*:*:*:*:*:*","versionEndIncluding":"8.0.27","matchCriteriaId":"6B9C558D-B200-45F2-9575-0816A10C58FA"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:*","matchCriteriaId":"5C2089EE-5D7F-47EC-8EA5-0F69790564C4"}]}]}],"references":[{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=1978810","source":"secalert@redhat.com","tags":["Issue 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