CVE-2021-20319

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-03-04 · updated 2026-06-17
Weakness: CWE-347

Description

An improper signature verification vulnerability was found in coreos-installer. A specially crafted gzip installation image can bypass the image signature verification and as a consequence can lead to the installation of unsigned content. An attacker able to modify the original installation image can write arbitrary data, and achieve full access to the node being installed.

Affected products

coreos-installer: before 0.10.1 — fixed in 0.10.1

How to fix

Upgrade to a fixed version: coreos-installer 0.10.1. Check the vendor advisory for mitigations.

References

https://bugzilla.redhat.com/show_bug.cgi?id=2011862
https://github.com/coreos/coreos-installer/pull/659/commits/ad243c6f0eff2835b2da56ca5f7f33af76253c89
https://github.com/coreos/coreos-installer/security/advisories/GHSA-3r3g-g73x-g593
https://bugzilla.redhat.com/show_bug.cgi?id=2011862
https://github.com/coreos/coreos-installer/pull/659/commits/ad243c6f0eff2835b2da56ca5f7f33af76253c89
https://github.com/coreos/coreos-installer/security/advisories/GHSA-3r3g-g73x-g593

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