CVE-2020-27222

Name: CVE-2020-27222
Creator: NVD / NIST
Published: 2021-02-03T16:15:13.117+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.85%

Last modified Jun 17, 2026

CVE-2020-27222 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. In Eclipse Californium version 2.3.0 to 2.6.0, the certificate based (x509 and RPK) DTLS handshakes accidentally fails, because the DTLS server side sticks to a wrong internal state. That wrong internal state is set by a previous certificate based DTLS handshake failure with TLS parameter mismatch. EPSS estimates a 0.85% chance of exploitation in the next 30 days.

Description

In Eclipse Californium version 2.3.0 to 2.6.0, the certificate based (x509 and RPK) DTLS handshakes accidentally fails, because the DTLS server side sticks to a wrong internal state. That wrong internal state is set by a previous certificate based DTLS handshake failure with TLS parameter mismatch. The DTLS server side must be restarted to recover this. This allow clients to force a DoS.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.85%

53.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-372

Affected Software

Vendor	Product	Versions
Eclipse	Californium	>= 2.3.0, <= 2.6.0

References

https://bugs.eclipse.org/bugs/show_bug.cgi?id=570844Permissions Required, Vendor Advisory
https://bugs.eclipse.org/bugs/show_bug.cgi?id=570844Permissions Required, Vendor Advisory

Timeline

Published: Feb 3, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27222?

How severe is CVE-2020-27222?

CVE-2020-27222 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.85% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27222?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-27222?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST