CVE-2025-56352

{"dataType": "CVE_RECORD", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2025-56352", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2026-05-18T17:27:28.823Z", "dateReserved": "2025-08-16T00:00:00.000Z", "datePublished": "2026-05-18T00:00:00.000Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2026-05-18T15:07:33.460Z"}, "descriptions": [{"lang": "en", "value": "In tinyMQTT commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18), the broker mishandles protocol violations during CONNECT packet parsing. When receiving a CONNECT packet with a zero-length Client ID while CleanSession is set to 0, the broker correctly replies with a CONNACK return code 0x02 (Identifier Rejected) but fails to explicitly close the TCP connection. Since the surrounding connection teardown logic is not guaranteed to execute, each such invalid CONNECT attempt leaves the underlying socket open. Repeated attempts cause server-side resource exhaustion due to accumulating file descriptors and memory usage, potentially resulting in denial of service."}], "affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"version": "n/a", "status": "affected"}]}], "references": [{"url": "https://github.com/JustDoIt0910/tinyMQTT/issues/19"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-400", "lang": "en", "description": "CWE-400 Uncontrolled Resource Consumption"}]}], "references": [{"url": "https://github.com/user-attachments/files/21207896/Resource_Exhaustion_Poc.txt", "tags": ["exploit"]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-05-18T17:22:27.393806Z", "id": "CVE-2025-56352", "options": [{"Exploitation": "poc"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-18T17:27:28.823Z"}}]}, "dataVersion": "5.2"}

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{"affected": [{"affectedData": [{"product": "n/a", "vendor": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "source": "cve@mitre.org"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In tinyMQTT commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18), the broker mishandles protocol violations during CONNECT packet parsing. When receiving a CONNECT packet with a zero-length Client ID while CleanSession is set to 0, the broker correctly replies with a CONNACK return code 0x02 (Identifier Rejected) but fails to explicitly close the TCP connection. Since the surrounding connection teardown logic is not guaranteed to execute, each such invalid CONNECT attempt leaves the underlying socket open. Repeated attempts cause server-side resource exhaustion due to accumulating file descriptors and memory usage, potentially resulting in denial of service."}, {"lang": "es", "value": "En el commit 6226ade15bd4f97be2d196352e64dd10937c1962 (2024-02-18) de tinyMQTT, el broker maneja incorrectamente las violaciones del protocolo durante el an\u00e1lisis de paquetes CONNECT. Al recibir un paquete CONNECT con un ID de cliente de longitud cero mientras CleanSession est\u00e1 configurado en 0, el broker responde correctamente con un c\u00f3digo de retorno CONNACK 0x02 (Identificador Rechazado) pero no cierra expl\u00edcitamente la conexi\u00f3n TCP. Dado que la l\u00f3gica de cierre de conexi\u00f3n circundante no est\u00e1 garantizada para ejecutarse, cada intento CONNECT inv\u00e1lido de este tipo deja el socket subyacente abierto. Los intentos repetidos causan el agotamiento de recursos del lado del servidor debido a la acumulaci\u00f3n de descriptores de archivo y el uso de memoria, lo que puede resultar en una denegaci\u00f3n de servicio."}], "id": "CVE-2025-56352", "lastModified": "2026-11-04T20:10:00.263", "metrics": {"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": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2025-56352", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-05-18T17:22:27.393806Z", "version": "2.0.3"}}]}, "published": "2026-05-18T16:16:29.130", "references": [{"source": "cve@mitre.org", "url": "https://github.com/JustDoIt0910/tinyMQTT/issues/19"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "url": "https://github.com/user-attachments/files/21207896/Resource_Exhaustion_Poc.txt"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": null}], "enrichment": {"confidence": 85.0, "confidence_source": "inferred", "scores": [{"score": 85.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "n/a", "source": "cna", "vendor": "n/a"}, "product": "tinymqtt", "vendor": "justdoit0910"}], "created": "2026-05-18T17:00:13.930486+00:00", "title": "tinyMQTT Broker Resource Exhaustion via Malformed CONNECT Packet", "updated": "2026-05-18T21:30:15.887857+00:00", "vendors": ["justdoit0910", "justdoit0910$PRODUCT$tinymqtt"]}