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TI-2021-18650 Aliases CVE-2021-42143GHSA-23p4-xxgc-xqvf

An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97.

Priority MEDIUM 41CWE-835Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
High · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA. Impact type from CWE-835.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00812 57th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
——all versions—No fix listedCNA
  • — Vendor— Affected all versions Fixed in — No fix listed CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:contiki-ng:tinydtls:*:*:*:*:*:*:*:*up to 2018-08-30Vulnerablecontiki-ng
  • cpe:2.3:a:contiki-ng:tinydtls:*:*:*:*:*:*:*:* Versions up to 2018-08-30 Vulnerable ·contiki-ng

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-42143
  2. 2026-10-03 Alias added: GHSA-23p4-xxgc-xqvf

References

Advisory 1

  • TI-2021-18649 An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. CVSS 3.1CRITICAL 9.8
  • TI-2021-18654 Buffer over-read vulnerability in the dtls_sha256_update function in Contiki-NG tinyDTLS… CVSS 3.1CRITICAL 9.1
  • TI-2021-18648 An issue was discovered in Contiki-NG tinyDTLS through 2018-08-30. CVSS 3.1CRITICAL 9.8
  • TI-2021-18653 An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. CVSS 3.1HIGH 7.5
  • TI-2021-18652 An assertion failure discovered in in check_certificate_request() in Contiki-NG tinyDTLS… CVSS 3.1HIGH 7.5

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences