No exploitation reportedFix available

CVE-2021-42141

No exploitation reported by the sources we read.

Published2024-01-22
WeaknessCWE-755

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in Contiki-NG tinyDTLS through 2018-08-30. One incorrect handshake could complete with different epoch numbers in the packets Client_Hello, Client_key_exchange, and Change_cipher_spec, which may cause denial of service.

Timeline

dates in UTC

2024-01-2223:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-42141?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-42141?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Contiki-ng tinydtls

Branch	Affected	Fixed in	Source
2018.x	≤ 2018-08-30	no fix published	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Advisories and patches

github.comPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2024-01-24
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.17.52025-06-20
NVDCVSS 3.19.8read 2026-10-23
CISA-ADPweakness (CWE)CWE-7552025-06-20
NVDweakness (CWE)CWE-755read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2024-01-22
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2021-42141?

Is CVE-2021-42141 actively exploited?

Active exploitation of CVE-2021-42141 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-42141?

CVE-2021-42141 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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