# CVE-2023-49721: Security feature bypass in LXD

> An insecure default in LXD allows OS-resident attackers to bypass Secure Boot by enabling the UEFI Shell.

- **Severity:** Medium 6.7 (`CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 14 Feb 2024
- **Updated:** 24 Oct 2024
- **Also known as:** GHSA-4639-7gfm-29p2, OESA-2026-4033, OESA-2026-4217

## What is CVE-2023-49721?

CVE-2023-49721 is a medium-severity vulnerability in Canonical Ltd. LXD, published on 14 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

An insecure default to allow UEFI Shell in EDK2 was left enabled in LXD. This allows an OS-resident attacker to bypass Secure Boot.

Weakness: CWE-276 (Incorrect Default Permissions)

## Which versions are affected by CVE-2023-49721?

It affects 2 products.


Products: Canonical Lxd, Tianocore Edk2.

## How do I fix CVE-2023-49721?

Apply the vendor's patch.

## Is CVE-2023-49721 being exploited?

There is no known exploitation of CVE-2023-49721 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ltd. LXD

- [CVE-2026-66897](https://insights.sbomify.com/CVE-2026-66897/): Instance template path traversal allows arbitrary host file write as root (critical 9.9)
- [CVE-2026-62420](https://insights.sbomify.com/CVE-2026-62420/): Cross-project cluster migration bypasses project restrictions via cluster notification flag (critical 9.9)
- [CVE-2026-63293](https://insights.sbomify.com/CVE-2026-63293/): Arbitrary File Read/Write: metadata.yaml symlink in image allows host filesystem access as root (critical 9.9)
- [CVE-2026-63294](https://insights.sbomify.com/CVE-2026-63294/): Root RCE via image backup.yaml symlink (critical 9.9)
- [CVE-2026-63296](https://insights.sbomify.com/CVE-2026-63296/): Project restriction bypass via instance migration config override (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-49721 and fix it if it is affected.

What it is: CVE-2023-49721 is a medium-severity vulnerability in Canonical Ltd. LXD, published on 14 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-49721 in the wild and no public exploit code.

Affected product: Canonical Ltd. LXD. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2023-49721/ (Markdown: https://insights.sbomify.com/CVE-2023-49721/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-49721
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-49721
- OSV: https://osv.dev/vulnerability/CVE-2023-49721

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-49721/
Summaries are generated and may contain mistakes; the official description above is the record.