GHSA-3g2j-vm47-x4mj

Source

https://github.com/advisories/GHSA-3g2j-vm47-x4mj

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2025/11/GHSA-3g2j-vm47-x4mj/GHSA-3g2j-vm47-x4mj.json

JSON Data

https://api.test.osv.dev/v1/vulns/GHSA-3g2j-vm47-x4mj

Published

2025-11-13T23:01:44Z

Modified

2025-11-13T23:01:44Z

Severity

8.6 (High) CVSS_V4 - CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N CVSS Calculator

Summary

LXD vulnerable to a local privilege escalation through custom storage volumes

Details

Impact

This affects any LXD user in an environment where an unprivileged user may have root access to a container with an attached custom storage volume that has the security.shifted property set to true as well as access to the host as an unprivileged user.

The most common case for this would be systems using lxd-user with the less privileged lxd group to provide unprivileged users with an isolated restricted access to LXD. Such users may be able to create a custom storage volume with the necessary property (depending on kernel and filesystem support) and can then write a setuid binary from within the container which can be executed as an unprivileged user on the host to gain root privileges.

Patches

Patches for this issue are available:

LXD 6 series: https://github.com/canonical/lxd/pull/16904
LXD 5.21 LTS series: https://github.com/canonical/lxd/pull/16922
LXD 5.0 LTS series: https://github.com/canonical/lxd/pull/16923
LXD 4.0 LTS series: https://github.com/canonical/lxd/pull/16924

The first commit changes the permissions for any new storage pool, the later commit adds a patch that applies it on startup to all existing storage pools.

These fixes are also available in the associated candidate snap channels for each LTS series:

5.21/candidate (5.21.4-8a3cf61)
5.0/candidate (5.0.5-5c60378)
4.0/candidate (4.0.10-35a8127)

We will be preparing intermediate releases to the associated stable snap channels shortly.

Workarounds

Permissions can be manually restricted until a patched version of LXD is deployed.

This is done with:

sudo nsenter --mount=/run/snapd/ns/lxd.mnt -- chmod 0700 /var/snap/lxd/common/lxd/storage-pools/*/{custom*,virtual-machines*,images}
sudo nsenter --mount=/run/snapd/ns/lxd.mnt -- chmod 0711 /var/snap/lxd/common/lxd/storage-pools/*/{containers*,buckets*}

Those are the same permissions which will be applied by the patched LXD for both new and existing storage pools.

References

This was reported to Incus publicly on Github here:

https://github.com/lxc/incus/security/advisories/GHSA-56mx-8g9f-5crf
https://github.com/lxc/incus/issues/2641

Database specific

{
    "cwe_ids": [
        "CWE-269"
    ],
    "nvd_published_at": null,
    "github_reviewed_at": "2025-11-13T23:01:44Z",
    "severity": "HIGH",
    "github_reviewed": true
}

References

Affected packages

Go / lxd

Package

Name: lxd; View open source insights on deps.dev
Purl: pkg:golang/lxd

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Last affected

6.18.0