CVE-2021-29430

{"containers": {"cna": {"affected": [{"product": "sydent", "vendor": "matrix-org", "versions": [{"status": "affected", "version": "< 2.3.0"}]}], "descriptions": [{"lang": "en", "value": "Sydent is a reference Matrix identity server. Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to memory exhaustion and denial of service. Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service. This affects any server which accepts registration requests from untrusted clients. This issue has been patched by releases 89071a1, 0523511, f56eee3. As a workaround request sizes can be limited in an HTTP reverse-proxy. There are no known workarounds for the problem with overlarge responses."}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "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:H", "version": "3.1"}}], "problemTypes": [{"descriptions": [{"cweId": "CWE-20", "description": "{\"CWE-20\":\"Improper Input Validation\"}", "lang": "en", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-400", "description": "CWE-400 Uncontrolled Resource Consumption", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"dateUpdated": "2021-04-15T20:35:19.000Z", "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M"}, "references": [{"tags": ["x_refsource_MISC"], "url": "https://pypi.org/project/matrix-sydent/"}, {"tags": ["x_refsource_CONFIRM"], "url": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428"}, {"tags": ["x_refsource_MISC"], "url": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0"}], "source": {"advisory": "GHSA-wmg4-8cp2-hpg9", "discovery": "UNKNOWN"}, "title": "Denial of service attack via memory exhaustion", "x_legacyV4Record": {"CVE_data_meta": {"ASSIGNER": "security-advisories@github.com", "ID": "CVE-2021-29430", "STATE": "PUBLIC", "TITLE": "Denial of service attack via memory exhaustion"}, "affects": {"vendor": {"vendor_data": [{"product": {"product_data": [{"product_name": "sydent", "version": {"version_data": [{"version_value": "< 2.3.0"}]}}]}, "vendor_name": "matrix-org"}]}}, "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": {"description_data": [{"lang": "eng", "value": "Sydent is a reference Matrix identity server. Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to memory exhaustion and denial of service. Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service. This affects any server which accepts registration requests from untrusted clients. This issue has been patched by releases 89071a1, 0523511, f56eee3. As a workaround request sizes can be limited in an HTTP reverse-proxy. There are no known workarounds for the problem with overlarge responses."}]}, "impact": {"cvss": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "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:H", "version": "3.1"}}, "problemtype": {"problemtype_data": [{"description": [{"lang": "eng", "value": "{\"CWE-20\":\"Improper Input Validation\"}"}]}, {"description": [{"lang": "eng", "value": "CWE-400 Uncontrolled Resource Consumption"}]}]}, "references": {"reference_data": [{"name": "https://pypi.org/project/matrix-sydent/", "refsource": "MISC", "url": "https://pypi.org/project/matrix-sydent/"}, {"name": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9", "refsource": "CONFIRM", "url": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9"}, {"name": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d", "refsource": "MISC", "url": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d"}, {"name": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7", "refsource": "MISC", "url": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7"}, {"name": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428", "refsource": "MISC", "url": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428"}, {"name": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0", "refsource": "MISC", "url": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0"}]}, "source": {"advisory": "GHSA-wmg4-8cp2-hpg9", "discovery": "UNKNOWN"}}}, "adp": [{"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-03T22:02:51.883Z"}, "title": "CVE Program Container", "references": [{"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://pypi.org/project/matrix-sydent/"}, {"tags": ["x_refsource_CONFIRM", "x_transferred"], "url": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428"}, {"tags": ["x_refsource_MISC", "x_transferred"], "url": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0"}]}]}, "cveMetadata": {"assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "assignerShortName": "GitHub_M", "cveId": "CVE-2021-29430", "datePublished": "2021-04-15T20:35:19.000Z", "dateReserved": "2021-03-30T00:00:00.000Z", "dateUpdated": "2024-08-03T22:02:51.883Z", "state": "PUBLISHED"}, "dataType": "CVE_RECORD", "dataVersion": "5.1"}

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{"affected": [{"affectedData": [{"product": "sydent", "vendor": "matrix-org", "versions": [{"status": "affected", "version": "< 2.3.0"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:matrix:sydent:*:*:*:*:*:*:*:*", "matchCriteriaId": "C77C5A80-7302-49F8-8DAA-37B269691C9C", "versionEndExcluding": "2.3.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Sydent is a reference Matrix identity server. Sydent does not limit the size of requests it receives from HTTP clients. A malicious user could send an HTTP request with a very large body, leading to memory exhaustion and denial of service. Sydent also does not limit response size for requests it makes to remote Matrix homeservers. A malicious homeserver could return a very large response, again leading to memory exhaustion and denial of service. This affects any server which accepts registration requests from untrusted clients. This issue has been patched by releases 89071a1, 0523511, f56eee3. As a workaround request sizes can be limited in an HTTP reverse-proxy. There are no known workarounds for the problem with overlarge responses."}, {"lang": "es", "value": "Sydent es un servidor de identidad Matrix de referencia.&#xa0;Sydent no limita el tama\u00f1o de las peticiones que recibe de los clientes HTTP.&#xa0;Un usuario malicioso podr\u00eda enviar una petici\u00f3n HTTP con un cuerpo muy grande, conllevando al agotamiento de la memoria y una denegaci\u00f3n de servicio.&#xa0;Sydent tampoco limita el tama\u00f1o de respuesta para las peticiones que realiza a los servidores dom\u00e9sticos de Matrix remotos.&#xa0;Un servidor dom\u00e9stico malicioso podr\u00eda devolver una respuesta muy grande, lo que nuevamente conlleva al agotamiento de la memoria y a una denegaci\u00f3n de servicio.&#xa0;Esto afecta a cualquier servidor que acepte peticiones de registro de clientes no confiables.&#xa0;Este problema ha sido parcheado para las versiones 89071a1, 0523511, f56eee3.&#xa0;Como soluci\u00f3n alternativa, los tama\u00f1os de las peticiones pueden ser limitados en un proxy inverso HTTP.&#xa0;No se conocen soluciones alternativas para el problema de las respuestas demasiado grandes"}], "id": "CVE-2021-29430", "lastModified": "2026-06-17T03:47:37.550", "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": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "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:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "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:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2021-04-15T21:15:17.413", "references": [{"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7"}, {"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d"}, {"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428"}, {"source": "security-advisories@github.com", "tags": ["Release Notes", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0"}, {"source": "security-advisories@github.com", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9"}, {"source": "security-advisories@github.com", "tags": ["Product", "Third Party Advisory"], "url": "https://pypi.org/project/matrix-sydent/"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/commit/0523511d2fb40f2738f8a8549868f44b96e5dab7"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/commit/89071a1a754c69a50deac89e6bb74002d4cda19d"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/commit/f56eee315b6c44fdd9f6aa785cc2ec744a594428"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Release Notes", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/releases/tag/v2.3.0"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch", "Third Party Advisory"], "url": "https://github.com/matrix-org/sydent/security/advisories/GHSA-wmg4-8cp2-hpg9"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Product", "Third Party Advisory"], "url": "https://pypi.org/project/matrix-sydent/"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-20"}, {"lang": "en", "value": "CWE-400"}], "source": "security-advisories@github.com", "type": "Secondary"}, {"description": [{"lang": "en", "value": "CWE-770"}], "source": "nvd@nist.gov", "type": "Primary"}]}

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