GHSA-3r3g-g73x-g593
HIGHcoreos-installer improperly verifies GPG signature when decompressing gzipped artifact
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
coreos-installerReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
Impact
coreos-installer fails to correctly verify GPG signatures when decompressing gzip-compressed artifacts. This allows bypass of signature verification in cases where coreos-installer decompresses a downloaded OS image, allowing an attacker who can modify the OS image to compromise a newly-installed system.
Default installations from ISO or PXE media in Fedora CoreOS, RHEL CoreOS, and RHEL for Edge are not affected, as coreos-installer installs from an OS image shipped as part of the install media.
These flows are affected:
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Installing with
--image-file,--image-url, orcoreos.inst.image_url. For example, if a user has a local mirror of installation images, an attacker could replace an image with a gzip-compressed alternative (even if the file extension is.xz). The result:$ coreos-installer install --image-url http://localhost:8080/image.xz /dev/loop0 Downloading image from http://localhost:8080/image.xz Downloading signature from http://localhost:8080/image.xz.sig > Read disk 749.9 MiB/749.9 MiB (100%) gpg: Signature made Mon 20 Sep 2021 02:41:50 PM EDT gpg: using RSA key 8C5BA6990BDB26E19F2A1A801161AE6945719A39 gpg: BAD signature from "Fedora (34) <[email protected]>" [ultimate] Install complete.Notice that GPG reports a bad signature, but coreos-installer continues anyway. Automation that relies on coreos-installer's exit status will not notice either.
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coreos-installer download --decompress --image-url:$ coreos-installer download --decompress --image-url http://localhost:8080/image.xz > Read disk 749.9 MiB/749.9 MiB (100%) gpg: Signature made Mon 20 Sep 2021 02:41:50 PM EDT gpg: using RSA key 8C5BA6990BDB26E19F2A1A801161AE6945719A39 gpg: BAD signature from "Fedora (34) <[email protected]>" [ultimate] ./imageAgain, coreos-installer reports success.
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Installing with default parameters, when not installing from the image built into live ISO or PXE media, if the hosting service is compromised or if an active attacker gains control of the HTTPS response.
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coreos-installer download --decompressif the hosting service is compromised or if an active attacker gains control of the HTTPS response.
Patches
The vulnerability is fixed in coreos-installer 0.10.1.
Workarounds
For coreos-installer download, do not use the -d or --decompress options.
For coreos-installer install, manually inspect the stderr output. If BAD signature appears, do not boot from the target disk. Note, however, that some OS services may have already accessed data on the compromised disk.
References
For more information, see PR 655.
For more information
If you have any questions or comments about this advisory, open an issue in coreos-installer or email the CoreOS development mailing list.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | coreos-installer | all versions | 0.10.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for coreos-installer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update coreos-installer to 0.10.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-3r3g-g73x-g593 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-3r3g-g73x-g593 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-3r3g-g73x-g593. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-3r3g-g73x-g593 in your dependencies?
O3 detects GHSA-3r3g-g73x-g593 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.