{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-04-18T18:37:36.393","vulnerabilities":[{"cve":{"id":"CVE-2021-21393","sourceIdentifier":"security-advisories@github.com","published":"2021-04-12T22:15:13.227","lastModified":"2024-11-21T05:48:16.003","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"Synapse is a Matrix reference homeserver written in python (pypi package matrix-synapse). Matrix is an ecosystem for open federated Instant Messaging and VoIP. In Synapse before version 1.28.0 Synapse is missing input validation of some parameters on the endpoints used to confirm third-party identifiers could cause excessive use of disk space and memory leading to resource exhaustion. Note that the groups feature is not part of the Matrix specification and the chosen maximum lengths are arbitrary. Not all clients might abide by them. Refer to referenced GitHub security advisory for additional details including workarounds."},{"lang":"es","value":"Synapse es un servidor doméstico de referencia de Matrix escrito en python (paquete pypi matrix-synapse). Matrix es un ecosistema para VoIP y mensajería instantánea federada abierta. En Synapse versiones anteriores a 1.28.0. Synapse presenta una falta de comprobación de entrada de algunos parámetros en los endpoints usados para confirmar que los identificadores de terceros podrían causar un uso excesivo del espacio en disco y la memoria conllevando a un agotamiento de los recursos. Note que la funcionalidad de grupos no forma parte de la especificación de Matrix y que las longitudes máximas elegidas son arbitrarias. No todos los clientes pueden acatarlos. Consulte el aviso de seguridad de GitHub al que se hace referencia para obtener detalles adicionales, incluyendo las soluciones"}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":1.6,"impactScore":3.6},{"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:M/Au:N/C:N/I:N/A:P","baseScore":4.3,"accessVector":"NETWORK","accessComplexity":"MEDIUM","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL"},"baseSeverity":"MEDIUM","exploitabilityScore":8.6,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-20"}]},{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"CWE-20"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*","versionStartExcluding":"0.24.0","versionEndExcluding":"1.28.0","matchCriteriaId":"B973D697-BF35-4DCF-AD93-9AEBAE62270E"}]}]},{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*","matchCriteriaId":"A930E247-0B43-43CB-98FF-6CE7B8189835"}]}]}],"references":[{"url":"https://github.com/matrix-org/synapse/pull/9321","source":"security-advisories@github.com","tags":["Patch","Third Party Advisory"]},{"url":"https://github.com/matrix-org/synapse/pull/9393","source":"security-advisories@github.com","tags":["Patch","Third Party Advisory"]},{"url":"https://github.com/matrix-org/synapse/security/advisories/GHSA-jrh7-mhhx-6h88","source":"security-advisories@github.com","tags":["Patch","Third Party Advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/","source":"security-advisories@github.com"},{"url":"https://pypi.org/project/matrix-synapse/","source":"security-advisories@github.com","tags":["Product","Third Party Advisory"]},{"url":"https://github.com/matrix-org/synapse/pull/9321","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch","Third Party Advisory"]},{"url":"https://github.com/matrix-org/synapse/pull/9393","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch","Third Party Advisory"]},{"url":"https://github.com/matrix-org/synapse/security/advisories/GHSA-jrh7-mhhx-6h88","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Patch","Third Party Advisory"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://pypi.org/project/matrix-synapse/","source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Product","Third Party Advisory"]}]}}]}