# CVE-2020-27352: Privilege escalation in snapd

> Attackers can gain unintended privileges in snapd-managed containers due to missing systemd delegation settings during unit reloads.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Jun 2024
- **Updated:** 4 Aug 2024
- **Also known as:** DEBIAN-CVE-2020-27352, GHSA-3hqj-7v65-62fj, UBUNTU-CVE-2020-27352, USN-4728-1

## What is CVE-2020-27352?

CVE-2020-27352 is a critical vulnerability in Canonical Ubuntu Linux, published on 21 Jun 2024. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

When generating the systemd service units for the docker snap (and other similar snaps), snapd does not specify Delegate=yes - as a result systemd will move processes from the containers created and managed by these snaps into the cgroup of the main daemon within the snap itself when reloading system units. This may grant additional privileges to a container within the snap that were not originally intended.

Weakness: CWE-269 (Improper Privilege Management)

## Which versions are affected by CVE-2020-27352?

It affects 2 products.


Products: Canonical Snapd, Canonical Ubuntu Linux.

## How do I fix CVE-2020-27352?

Apply the vendor's patch.

## Is CVE-2020-27352 being exploited?

There is no known exploitation of CVE-2020-27352 in the wild and no public exploit code.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2023-1523](https://insights.sbomify.com/CVE-2023-1523/): Command injection in snapd (critical 10.0)
- [CVE-2019-7304](https://insights.sbomify.com/CVE-2019-7304/): Local privilege escalation via snapd socket (high 8.8)
- [CVE-2021-4120](https://insights.sbomify.com/CVE-2021-4120/): snapd could be made to bypass intended access restrictions through snap content interfaces and layout paths (high 8.2)
- [CVE-2024-5138](https://insights.sbomify.com/CVE-2024-5138/): CVE-2024-5138: snapd snapctl auth bypass (high 8.1)
- [CVE-2022-3328](https://insights.sbomify.com/CVE-2022-3328/): snapd Race Condition vulnerability (high 7.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-27352 and fix it if it is affected.

What it is: CVE-2020-27352 is a critical vulnerability in Canonical Ubuntu Linux, published on 21 Jun 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-2020-27352 in the wild and no public exploit code.

Affected product: Canonical Ubuntu Linux. 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-2020-27352/ (Markdown: https://insights.sbomify.com/CVE-2020-27352/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-27352
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-27352
- OSV: https://osv.dev/vulnerability/CVE-2020-27352

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-27352/
Summaries are generated and may contain mistakes; the official description above is the record.