CVE-2021-42143 - Vulnerability Details - OpenCVE

An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. An infinite loop bug exists during the handling of a ClientHello handshake message. This bug allows remote attackers to cause a denial of service by sending a malformed ClientHello handshake message with an odd length of cipher suites, which triggers an infinite loop (consuming all resources) and a buffer over-read that can disclose sensitive information.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact High

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00354.

Exploitation none

Automatable no

Technical Impact partial

Vendors	Products
Contiki-ng	Tinydtls

Configuration 1 [-]

cpe:2.3:a:contiki-ng:tinydtls:*:*:*:*:*:*:*:*

No data.

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References

Link	Providers
http://seclists.org/fulldisclosure/2024/Jan/16
https://seclists.org/fulldisclosure/2024/Jan/16

History

Fri, 20 Jun 2025 20:15:00 +0000

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Fri, 22 Nov 2024 12:00:00 +0000

Type	Values Removed	Values Added
References		http://seclists.org/fulldisclosure/2024/Jan/16

MITRE

Status: PUBLISHED

Assigner: mitre

Published: 2024-01-24T00:00:00.000Z

Updated: 2025-06-20T19:16:00.614Z

Reserved: 2021-10-11T00:00:00.000Z

Link: CVE-2021-42143

Vulnrichment

Updated: 2024-08-04T03:30:37.578Z

NVD

Status : Modified

Published: 2024-01-24T18:15:08.080

Modified: 2025-06-20T20:15:21.900

Link: CVE-2021-42143

Redhat

No data.

OpenCVE Enrichment

No data.

{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"state": "PUBLISHED", "cveId": "CVE-2021-42143", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "assignerShortName": "mitre", "dateUpdated": "2025-06-20T19:16:00.614Z", "dateReserved": "2021-10-11T00:00:00.000Z", "datePublished": "2024-01-24T00:00:00.000Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2024-01-24T17:53:40.614Z"}, "descriptions": [{"lang": "en", "value": "An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. An infinite loop bug exists during the handling of a ClientHello handshake message. This bug allows remote attackers to cause a denial of service by sending a malformed ClientHello handshake message with an odd length of cipher suites, which triggers an infinite loop (consuming all resources) and a buffer over-read that can disclose sensitive information."}], "affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"version": "n/a", "status": "affected"}]}], "references": [{"url": "https://seclists.org/fulldisclosure/2024/Jan/16"}], "problemTypes": [{"descriptions": [{"type": "text", "lang": "en", "description": "n/a"}]}]}, "adp": [{"title": "CVE Program Container", "references": [{"url": "http://seclists.org/fulldisclosure/2024/Jan/16"}, {"url": "https://seclists.org/fulldisclosure/2024/Jan/16", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T03:30:37.578Z"}}, {"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-835", "lang": "en", "description": "CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2024-01-24T19:22:24.819809Z", "id": "CVE-2021-42143", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"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": "2025-06-20T19:16:00.614Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CVE Program Container", "references": [{"url": "http://seclists.org/fulldisclosure/2024/Jan/16"}, {"url": "https://seclists.org/fulldisclosure/2024/Jan/16", "tags": ["x_transferred"]}], "providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T03:30:37.578Z"}}, {"title": "CISA ADP Vulnrichment", "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"other": {"type": "ssvc", "content": {"id": "CVE-2021-42143", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2024-01-24T19:22:24.819809Z"}}}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-835", "description": "CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')"}]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-06-20T19:15:20.672Z"}}], "cna": {"affected": [{"vendor": "n/a", "product": "n/a", "versions": [{"status": "affected", "version": "n/a"}]}], "references": [{"url": "https://seclists.org/fulldisclosure/2024/Jan/16"}], "descriptions": [{"lang": "en", "value": "An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. An infinite loop bug exists during the handling of a ClientHello handshake message. This bug allows remote attackers to cause a denial of service by sending a malformed ClientHello handshake message with an odd length of cipher suites, which triggers an infinite loop (consuming all resources) and a buffer over-read that can disclose sensitive information."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "text", "description": "n/a"}]}], "providerMetadata": {"orgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "shortName": "mitre", "dateUpdated": "2024-01-24T17:53:40.614Z"}}}, "cveMetadata": {"cveId": "CVE-2021-42143", "state": "PUBLISHED", "dateUpdated": "2025-06-20T19:16:00.614Z", "dateReserved": "2021-10-11T00:00:00.000Z", "assignerOrgId": "8254265b-2729-46b6-b9e3-3dfca2d5bfca", "datePublished": "2024-01-24T00:00:00.000Z", "assignerShortName": "mitre"}, "dataVersion": "5.1"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:contiki-ng:tinydtls:*:*:*:*:*:*:*:*", "matchCriteriaId": "E938DF84-2663-4516-87E3-B7E46789F6A1", "versionEndIncluding": "2018-08-30", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. An infinite loop bug exists during the handling of a ClientHello handshake message. This bug allows remote attackers to cause a denial of service by sending a malformed ClientHello handshake message with an odd length of cipher suites, which triggers an infinite loop (consuming all resources) and a buffer over-read that can disclose sensitive information."}, {"lang": "es", "value": "Se descubri\u00f3 un problema en Contiki-NG tinyDTLS a trav\u00e9s de la rama maestra 53a0d97. Existe un error de bucle infinito durante el manejo de un mensaje de protocolo de enlace ClientHello. Este error permite a atacantes remotos provocar una denegaci\u00f3n de servicio enviando un mensaje de protocolo de enlace ClientHello mal formado con una longitud impar de conjuntos de cifrado, lo que desencadena un bucle infinito (consumiendo todos los recursos) y una sobrelectura del b\u00fafer que puede revelar informaci\u00f3n confidencial."}], "id": "CVE-2021-42143", "lastModified": "2025-06-20T20:15:21.900", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "nvd@nist.gov", "type": "Primary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2024-01-24T18:15:08.080", "references": [{"source": "cve@mitre.org", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://seclists.org/fulldisclosure/2024/Jan/16"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "http://seclists.org/fulldisclosure/2024/Jan/16"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Mailing List", "Third Party Advisory"], "url": "https://seclists.org/fulldisclosure/2024/Jan/16"}], "sourceIdentifier": "cve@mitre.org", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-835"}], "source": "nvd@nist.gov", "type": "Primary"}, {"description": [{"lang": "en", "value": "CWE-835"}], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}