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

published 2024-01-23 2 y ago modified 2026-06-17 4 mo ago also EUVD-2021-29125

cvss: 8.2; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.0%; EPSS 1.0% chance of exploitation in 30 days, percentile 62%
public exploits: 0; none known

An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. DTLS servers mishandle the early use of a large epoch number. This vulnerability allows remote attackers to cause a denial of service and false-positive packet drops.

Patch / fix

links 1

github.com/contiki-ng/tinydtls/issues/24 patch

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: total
Assessed: 2 y ago (2024-10-21)

Exploit prediction

0.99% chance of exploitation in the next 30 days, higher than 62% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	8.2	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA	3.1	8.2	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

Classification

Weakness

CWE-770 Allocation of Resources Without Limits or Throttling
CWE-755 Improper Handling of Exceptional Conditions

References

github.com /contiki-ng/tinydtls/issues/24
issue-tracking, patch
seclists.org /fulldisclosure/2024/Jan/15
mailing-list, third-party-advisory
seclists.org /fulldisclosure/2024/Jan/15

Sources

CVE List CVE-2021-42142
NVD CVE-2021-42142

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary