{"cve":"CVE-2021-42143","nvd":{"published":"2024-01-24T18:15:08.080","modified":"2026-06-17T04:09:25.390","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H","score":9.1},"cwes":["CWE-835"],"references":["https://seclists.org/fulldisclosure/2024/Jan/16","http://seclists.org/fulldisclosure/2024/Jan/16","https://seclists.org/fulldisclosure/2024/Jan/16"],"products":["contiki-ng:tinydtls"],"source":"nvd","synced_at":"2026-10-19T21:44:57.175229480+00:00"},"epss":{"cve":"CVE-2021-42143","score":0.00812,"percentile":0.56992,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}