CVE-2021-41091: Github.com/moby/moby Moby (Docker Engine) Insufficiently Restricted Vulnerability
MODERATECVE-2021-41091 is a MODERATE (CVSS 5.9) moby (docker engine) insufficiently restricted vulnerability (CWE-732: Incorrect Permission Assignment for Critical Resource) affecting Github.com/moby/moby libraries in the Go ecosystem. The issue involves moby (docker engine) insufficiently restricted permissions on data directory. Remediation is available by upgrading affected packages to version 20.10.9.
CVE-2021-41091 at a Glance
Security Impact
CVSS: 5.9
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).
How to Fix CVE-2021-41091
To remediate this vulnerability, upgrade all affected Github.com/moby/moby 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 github.com/moby/moby to 20.10.9
Upgrade github.com/docker/docker to 20.10.9
Run the following command in your project directory to verify that all resolved dependencies use the patched release:
inspect dependencies for github.com/moby/moby
How to Check if You Are Affected
To determine whether your application is affected by CVE-2021-41091, inspect your project dependencies for Github.com/moby/moby:
inspect dependencies for github.com/moby/moby
Analyze the terminal output to locate any version of Github.com/moby/moby in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 20.10.9), 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-732: Incorrect Permission Assignment for Critical Resource, where the product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors. In Github.com/moby/moby, 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-2021-41091 Affected Github.com/moby/moby Versions
2 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
github.com/moby/moby
|
Go |
< 20.10.9
|
20.10.9
|
|
github.com/docker/docker
|
Go |
< 20.10.9
|
20.10.9
|
References
Frequently Asked Questions
What is CVE-2021-41091?
Which Github.com/moby/moby versions are affected?
What version fixes CVE-2021-41091?
Is github.com/moby/moby affected?
Is github.com/docker/docker affected?
What is the CVSS score of CVE-2021-41091?
What CWE is associated with CVE-2021-41091?
How can I check Go dependencies for CVE-2021-41091?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-3fwx-pjgw-3558",
"modified" : "2024-05-14T22:00:30Z",
"published" : "2024-01-31T23:28:58Z",
"aliases" : [ "CVE-2021-41091" ],
"summary" : "Moby (Docker Engine) Insufficiently restricted permissions on data directory",
"details" : "## Impact\n\nA bug was found in Moby (Docker Engine) where the data directory (typically `/var/lib/docker`) contained subdirectories with insufficiently restricted permissions, allowing otherwise unprivileged Linux users to traverse directory contents and execute programs. When containers included executable programs with extended permission bits (such as `setuid`), unprivileged Linux users could discover and execute those programs. When the UID of an unprivileged Linux user on the host collided with the file owner or group inside a container, the unprivileged Linux user on the host could discover, read, and modify those files.\n\n## Patches\n\nThis bug has been fixed in Moby (Docker Engine) 20.10.9. Users should update to this version as soon as possible. Running containers should be stopped and restarted for the permissions to be fixed.\n\n## Workarounds\n\nLimit access to the host to trusted users. Limit access to host volumes to trusted containers.\n\n## Credits\n\nThe Moby project would like to thank Joan Bruguera for responsibly disclosing this issue in accordance with the [Moby security policy](https://github.com/moby/moby/blob/master/SECURITY.md).\n\n## For more information\n\nIf you have any questions or comments about this advisory:\n\n* [Open an issue](https://github.com/moby/moby/issues/new)\n* Email us at security@docker.com if you think you’ve found a security bug",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/moby/moby"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "20.10.9"
} ]
} ]
}, {
"package" : {
"ecosystem" : "Go",
"name" : "github.com/docker/docker"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "20.10.9"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/moby/moby/security/advisories/GHSA-3fwx-pjgw-3558"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-41091"
}, {
"type" : "WEB",
"url" : "https://github.com/moby/moby/commit/f0ab919f518c47240ea0e72d0999576bb8008e64"
}, {
"type" : "WEB",
"url" : "https://cert-portal.siemens.com/productcert/pdf/ssa-222547.pdf"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/moby/moby"
}, {
"type" : "WEB",
"url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/B5Q6G6I4W5COQE25QMC7FJY3I3PAYFBB"
}, {
"type" : "WEB",
"url" : "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/ZNFADTCHHYWVM6W4NJ6CB4FNFM2VMBIB"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-281", "CWE-732" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2024-01-31T23:28:58Z",
"nvd_published_at" : "2021-10-04T21:15:00Z"
}
}