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Fencer Vulns
high 7.5

CVE-2020-27222 json

In Eclipse Californium version 2.3.0 to 2.6.0, the certificate based (x509 and RPK) DTLS handshakes accidentally fails, because the DTLS se…

published 2021-02-03 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19737

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.9%
EPSS 0.9% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-27222 updated cvss 7.5

californium-core: DTLS - DoS vulnerability for certificate based handshakes

  • Red Hat Fuse 7 californium-core californium-core Red Hat Integration Camel K 1 californium-core californium-core Red Hat Integration Camel Quarkus 1 californium-core californium-core
    affected: no fix available
  • Red Hat Integration
    fixed: vendor fix RHSA-2021:3205
  • Red Hat Integration Camel Quarkus 2
    fixed: vendor fix RHSA-2021:3207
  • Red Hat JBoss Fuse 6 californium-core californium-core
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.86% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • The Eclipse Foundation Eclipse Californium

Classification

Weakness
  • CWE-372 Incomplete Internal State Distinction

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.