How severe is CVE-2021-42141?

CVE-2021-42141 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-42141 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-42141?

CVE-2021-42141 affects Contiki-ng Tinydtls. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-42141?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2021-42141 have an EU (EUVD) identifier?

Yes. CVE-2021-42141 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-29124.

When was CVE-2021-42141 published?

CVE-2021-42141 was published on 2024-01-22 and last updated on 2026-06-17.

CVE-2021-42141

CVE-2021-42141 is a critical-severity vulnerability in Contiki-ng Tinydtls with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-755.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (64th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2021-29124
Weakness: CWE-755
Affected product: Contiki-ng Tinydtls
Published: 2024-01-22
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-42141?: 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.
How severe is CVE-2021-42141?: CVE-2021-42141 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-42141 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (64th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-42141?: CVE-2021-42141 affects Contiki-ng Tinydtls. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-42141?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2021-42141 have an EU (EUVD) identifier?: Yes. CVE-2021-42141 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2021-29124.
When was CVE-2021-42141 published?: CVE-2021-42141 was published on 2024-01-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:contiki-ng:tinydtls:*:*:*:*:*:*:*:*

More vulnerabilities in Contiki-ng Tinydtls

CVE-2021-42142 — Critical (CVSS 9.8): An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. DTLS servers mishandle the early use of a…
CVE-2021-42147 — Critical (CVSS 9.1): Buffer over-read vulnerability in the dtls_sha256_update function in Contiki-NG tinyDTLS through master branch 53a0d97…
CVE-2021-42143 — Critical (CVSS 9.1): An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. An infinite loop bug exists during the…
CVE-2021-42146 — High (CVSS 7.5): An issue was discovered in Contiki-NG tinyDTLS through master branch 53a0d97. DTLS servers allow remote attackers to…
CVE-2021-42145 — High (CVSS 7.5): An assertion failure discovered in in check_certificate_request() in Contiki-NG tinyDTLS through master branch 53a0d97…

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