CVE-2021-3917

Local secret disclosure via world-readable Ignition configuration

Published Aug 23, 2022 · Updated Aug 3, 2024

Information disclosure in CoreOS coreos-installer before 0.10.0 allows local users to read secrets from an installed Ignition config. The write_ignition routine in src/install.rs copies supplied data to /boot/ignition/config.ign without restricting inherited world-readable permissions. Default Fedora CoreOS and RHEL CoreOS installations have no unprivileged accounts; cloud-image and ignition.config.url deployments do not create this file.

CVSS severity5.5
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in CoreOS coreos-installer before 0.10.0 allows local users to read secrets from an installed Ignition config. The write_ignition routine in src/install.rs copies supplied data to /boot/ignition/config.ign without restricting inherited world-readable permissions. Default Fedora CoreOS and RHEL CoreOS installations have no unprivileged accounts; cloud-image and ignition.config.url deployments do not create this file.

The record

CVE
CVE-2021-3917
Published
Aug 23, 2022
Updated
Aug 3, 2024
Vendor
CoreOS
Product
coreos-installer
Classifications
CWE-276, CWE-277, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 23, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Fixed in coreos-installer 0.10.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

CoreOS · coreos-installerversion=Fixed in coreos-installer 0.10.0

Published CVSS scores

5.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-276Incorrect Default Permissions
CWE-277Insecure Inherited Permissions
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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