CVE-2021-29471

{"containers": {"cna": {"affected": [{"product": "synapse", "vendor": "matrix-org", "versions": [{"status": "affected", "version": "< 1.33.2"}]}], "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 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy."}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}], "problemTypes": [{"descriptions": [{"cweId": "CWE-400", "description": "CWE-400: Uncontrolled Resource Consumption", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"dateUpdated": "2021-08-02T02:06:25.000Z", "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M"}, "references": [{"tags": ["x_refsource_CONFIRM"], "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"}, {"name": "FEDORA-2021-a627cfd31e", "tags": ["vendor-advisory", "x_refsource_FEDORA"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"}], "source": {"advisory": "GHSA-x345-32rc-8h85", "discovery": "UNKNOWN"}, "title": "Denial of service in Matrix Synapse", "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "security-advisories@github.com", "ID": "CVE-2021-29471", "STATE": "PUBLIC", "TITLE": "Denial of service in Matrix Synapse"}, "affects": {"vendor": {"vendor_data": [{"product": {"product_data": [{"product_name": "synapse", "version": {"version_data": [{"version_value": "< 1.33.2"}]}}]}, "vendor_name": "matrix-org"}]}}, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": {"description_data": [{"lang": "eng", "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 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy."}]}, "impact": {"cvss": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "CWE-400: Uncontrolled Resource Consumption"}]}]}, "references": {"reference_data": [{"name": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85", "refsource": "CONFIRM", "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"}, {"name": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c", "refsource": "MISC", "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"}, {"name": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2", "refsource": "MISC", "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"}, {"name": "FEDORA-2021-a627cfd31e", "refsource": "FEDORA", "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"}]}, "source": {"advisory": "GHSA-x345-32rc-8h85", "discovery": "UNKNOWN"}}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T22:11:05.476Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_CONFIRM", "x_transferred"], "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"}, {"name": "FEDORA-2021-a627cfd31e", "tags": ["vendor-advisory", "x_refsource_FEDORA", "x_transferred"], "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"}]}]}, "cveMetadata": {"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "assignerShortName": "GitHub_M", "cveId": "CVE-2021-29471", "datePublished": "2021-05-11T15:05:12.000Z", "dateReserved": "2021-03-30T00:00:00.000Z", "dateUpdated": "2024-08-03T22:11:05.476Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

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{"affected": [{"affectedData": [{"product": "synapse", "vendor": "matrix-org", "versions": [{"status": "affected", "version": "< 1.33.2"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:matrix:synapse:*:*:*:*:*:*:*:*", "matchCriteriaId": "CA3C30EA-7826-48F6-9367-5632BE392B50", "versionEndExcluding": "1.33.2", "vulnerable": true}], "negate": false, "operator": "OR"}]}, {"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*", "matchCriteriaId": "A930E247-0B43-43CB-98FF-6CE7B8189835", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "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 1.33.2 \"Push rules\" can specify conditions under which they will match, including `event_match`, which matches event content against a pattern including wildcards. Certain patterns can cause very poor performance in the matching engine, leading to a denial-of-service when processing moderate length events. The issue is patched in version 1.33.2. A potential workaround might be to prevent users from making custom push rules, by blocking such requests at a reverse-proxy."}, {"lang": "es", "value": "Synapse es un servidor dom\u00e9stico de referencia de Matrix escrito en python (paquete pypi matrix-synapse). Matrix es un ecosistema para VoIP y mensajer\u00eda instant\u00e1nea federada abierta. En Synapse versiones anteriores a 1.33.2, unas \"Push rules\" pueden especificar condiciones bajo las cuales coincidir\u00e1n, incluyendo \"event_match\", que compara el contenido del evento con un patr\u00f3n que incluye comodines. Determinados patrones pueden causar un rendimiento muy deficiente en el motor de coincidencia, conllevando a una denegaci\u00f3n de servicio cuando se procesan eventos de duraci\u00f3n moderada. El problema est\u00e1 parcheado en versi\u00f3n 1.33.2. Una posible soluci\u00f3n alternativa podr\u00eda ser impedir a unos usuarios crear reglas de inserci\u00f3n personalizadas, al bloquear dichas peticiones en un proxy inverso"}], "id": "CVE-2021-29471", "lastModified": "2026-06-17T03:47:42.517", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "LOW", "accessVector": "NETWORK", "authentication": "NONE", "availabilityImpact": "PARTIAL", "baseScore": 5.0, "confidentialityImpact": "NONE", "integrityImpact": "NONE", "vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:P", "version": "2.0"}, "exploitabilityScore": 10.0, "impactScore": 2.9, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "nvd@nist.gov", "type": "Primary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 3.7, "baseSeverity": "LOW", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 1.4, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2021-05-11T15:15:08.507", "references": [{"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"}, {"source": "security-advisories@github.com", "tags": ["Release Notes", "Third Party Advisory"], "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"}, {"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"}, {"source": "security-advisories@github.com", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/synapse/commit/03318a766cac9f8b053db2214d9c332a977d226c"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Release Notes", "Third Party Advisory"], "url": "https://github.com/matrix-org/synapse/releases/tag/v1.33.2"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/synapse/security/advisories/GHSA-x345-32rc-8h85"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TNNAJOZNMVMXM6AS7RFFKB4QLUJ4IFEY/"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}], "source": "security-advisories@github.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-331"}], "source": "nvd@nist.gov", "type": "Primary"}]}

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