9.1

CVE-2021-42147: contiki-ng tinydtls Out-of-bounds Read

CVSS: 9.1v3.1CriticalModified
Published 24-01-2024Last modified 30-05-2025
Open JSON

Vulnerability summary

CVE-2021-42147 is a critical (CVSS 9.1) Out-of-bounds Read vulnerability in contiki-ng tinydtls. EPSS estimates a 0.84% chance of exploitation in the next 30 days, higher than 57.2% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.84%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 24-01-2024
    PublishedVulnerability first disclosed.
  2. 30-05-2025
    Last modifiedVulnerability information updated.

Description

Buffer over-read vulnerability in the dtls_sha256_update function in Contiki-NG tinyDTLS through master branch 53a0d97 allows remote attackers to cause a denial of service via crafted data packet.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.84%

Chance of exploitation in the next 30 days

Percentile

57%

Versus all other CVEs

30-day change

0.00 pp

From 0.84% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.84%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Contiki-ng1 product

1 vendor · 1 product

References

2 links