CVE-2021-42142: contiki-ng tinydtls
CVSS: 9.8v3.1CriticalModified
Published 23-01-2024Last modified 11-06-2025
Vulnerability summary
CVE-2021-42142 is a critical (CVSS 9.8) vulnerability in contiki-ng tinydtls. EPSS estimates a 0.99% chance of exploitation in the next 30 days, higher than 62% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (NVD)EPSS score
0.99%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 23-01-2024PublishedVulnerability first disclosed.
- 11-06-2025Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
2 scores · 2 sources · 1 versionCritical 9.8Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSources2 sources · 8.2–9.8
- CVE.orgCNA8.2HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:HDiffers
EPSS trend
Probability
0.99%
Chance of exploitation in the next 30 days
Percentile
62%
Versus all other CVEs
30-day change
0.00 pp
From 0.99% on 21-09-2026
21-09-202621-10-2026
EPSS score0.99%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-755Improper Handling of Exceptional ConditionsThe product does not handle or incorrectly handles an exceptional condition.
- CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.
Affected systems
Contiki-ng1 product
- tinydtls≤ 2018-08-30
1 vendor · 1 product