CVE-2021-3917: Coreos installer Coreos-installer < 0.10.0 Writes World-readable Vulnerability
MODERATECVE-2021-3917 is a MODERATE (CVSS 5.5) coreos-installer < 0.10.0 writes world-readable vulnerability (CWE-276: Incorrect Default Permissions) affecting Coreos installer libraries in the crates.io ecosystem. The issue involves coreos-installer < 0.10.0 writes world-readable ignition config to installed system. Remediation is available by upgrading affected packages to version 0.10.0.
CVE-2021-3917 at a Glance
Security Impact
CVSS: 5.5
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N).
How to Fix CVE-2021-3917
To remediate this vulnerability, upgrade all affected Coreos installer dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
Upgrade coreos-installer to 0.10.0
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for coreos-installer
How to Check if You Are Affected
To determine whether your application is affected by CVE-2021-3917, inspect your project dependencies for Coreos installer:
inspect dependencies for coreos-installer
Analyze the terminal output to locate any version of Coreos installer in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.10.0), your application is affected.
Note: Verify declared build manifests and deployed runtime container environments.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-276: Incorrect Default Permissions, where during installation, installed file permissions are set to allow anyone to modify those files. In Coreos installer, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2021-3917 Affected Coreos installer Versions
1 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
coreos-installer
|
crates.io |
< 0.10.0
|
0.10.0
|
References
Frequently Asked Questions
What is CVE-2021-3917?
Which Coreos installer versions are affected?
What version fixes CVE-2021-3917?
Is coreos-installer affected?
What is the CVSS score of CVE-2021-3917?
What CWE is associated with CVE-2021-3917?
How can I check crates.io dependencies for CVE-2021-3917?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-862g-9h5m-m3qv",
"modified" : "2022-09-08T14:25:48Z",
"published" : "2021-11-08T18:01:13Z",
"aliases" : [ "CVE-2021-3917" ],
"summary" : "coreos-installer < 0.10.0 writes world-readable Ignition config to installed system",
"details" : "### Impact\nOn systems installed with coreos-installer before 0.10.0, the user-provided Ignition config was written to `/boot/ignition/config.ign` with world-readable permissions, granting unprivileged users access to any secrets included in the config.\n\nDefault configurations of Fedora CoreOS and RHEL CoreOS do not include any unprivileged user accounts. In addition, instances launched from a cloud image, and systems provisioned with the `ignition.config.url` kernel argument, do not use the `config.ign` file and are unaffected.\n\n### Patches\ncoreos-installer 0.10.0 and later [writes](https://github.com/coreos/coreos-installer/pull/571) the Ignition config with restricted permissions.\n\n### Workarounds\n\nOn Fedora CoreOS systems installed from version 34.20210711.3.0 (stable), 34.20210711.2.0 (testing), 34.20210711.1.1 (next) and later, the `/boot/ignition` directory and its contents are removed after provisioning is complete. All Fedora CoreOS systems that have updated to these versions or later have automatically removed the `/boot/ignition` directory and no action is required.\n\nOn other systems, `/boot/ignition/config.ign` can be removed manually, as it is not used after provisioning is complete:\n\n```\nsudo mount -o remount,rw /boot\nsudo rm -rf /boot/ignition\n```\n\n### References\nFor more information, see https://github.com/coreos/fedora-coreos-tracker/issues/889.\n\n### For more information\nIf you have any questions or comments about this advisory, [open an issue in coreos-installer](https://github.com/coreos/coreos-installer/issues/new/choose) or email the CoreOS [development mailing list](https://lists.fedoraproject.org/archives/list/coreos@lists.fedoraproject.org/).",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "crates.io",
"name" : "coreos-installer"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "0.10.0"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/coreos/coreos-installer/security/advisories/GHSA-862g-9h5m-m3qv"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-3917"
}, {
"type" : "WEB",
"url" : "https://github.com/coreos/fedora-coreos-tracker/issues/889"
}, {
"type" : "WEB",
"url" : "https://github.com/coreos/coreos-installer/commit/2a36405339c87b16ed6c76e91ad5b76638fbdb0c"
}, {
"type" : "WEB",
"url" : "https://access.redhat.com/security/cve/CVE-2021-3917"
}, {
"type" : "WEB",
"url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2018478"
}, {
"type" : "WEB",
"url" : "https://github.com/coreos/coreos-installer"
}, {
"type" : "WEB",
"url" : "https://github.com/coreos/coreos-installer/releases/tag/v0.10.0"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-276" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2021-11-04T17:11:09Z",
"nvd_published_at" : "2022-08-23T20:15:00Z"
}
}