CVE-2021-42146: contiki-ng tinydtls
CVSS: 7.5v3.1HighModified
Published 24-01-2024Last modified 20-06-2025
Vulnerability summary
CVE-2021-42146 is a high (CVSS 7.5) vulnerability in contiki-ng tinydtls. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 50.9% of scored vulnerabilities.
CVSS score
7.5/10
010
High · v3.1 (CVE.org)EPSS score
0.66%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Timeline
- 24-01-2024PublishedVulnerability first disclosed.
- 20-06-2025Last modifiedVulnerability information updated.
Description
An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. DTLS servers allow remote attackers to reuse the same epoch number within two times the TCP maximum segment lifetime, which is prohibited in RFC6347. This vulnerability allows remote attackers to obtain sensitive application (data of connected clients).
CVSS metrics
2 scores · 2 sources · 1 versionHigh 7.5Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NSourcesAll 2 agree
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
0.66%
Chance of exploitation in the next 30 days
Percentile
51%
Versus all other CVEs
30-day change
0.00 pp
From 0.66% on 21-09-2026
21-09-202621-10-2026
EPSS score0.66%
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-303Incorrect Implementation of Authentication AlgorithmThe requirements for the product dictate the use of an established authentication algorithm, but the implementation of the algorithm is incorrect.
Affected systems
Contiki-ng1 product
- tinydtls2018-08-30
1 vendor · 1 product