# CVE-2023-1523: Command injection in snapd

> A malicious snap can inject commands into the controlling terminal on virtual consoles, allowing arbitrary code execution outside the sandbox.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/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:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 1 Sep 2023
- **Updated:** 1 Oct 2024
- **Also known as:** DEBIAN-CVE-2023-1523, GHSA-55wx-23fj-c2v5, UBUNTU-CVE-2023-1523, USN-6125-1

## What is CVE-2023-1523?

CVE-2023-1523 is a critical command injection vulnerability in Canonical Ubuntu Linux, published on 1 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Using the TIOCLINUX ioctl request, a malicious snap could inject contents into the input of the controlling terminal which could allow it to cause arbitrary commands to be executed outside of the snap sandbox after the snap exits. Graphical terminal emulators like xterm, gnome-terminal and others are not affected - this can only be exploited when snaps are run on a virtual console.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component)

## Which versions are affected by CVE-2023-1523?

It affects 2 products.


Products: Canonical Snapd, Canonical Ubuntu Linux.

## How do I fix CVE-2023-1523?

Apply the vendor's patch.

## Is CVE-2023-1523 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-1523 exists.

## Other vulnerabilities in Canonical Ubuntu Linux

- [CVE-2020-27352](https://insights.sbomify.com/CVE-2020-27352/): Privilege escalation in snapd (critical 9.3)
- [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-2023-1523 and fix it if it is affected.

What it is: CVE-2023-1523 is a critical command injection vulnerability in Canonical Ubuntu Linux, published on 1 Sep 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-1523 exists.

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-2023-1523/ (Markdown: https://insights.sbomify.com/CVE-2023-1523/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-1523
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-1523
- OSV: https://osv.dev/vulnerability/CVE-2023-1523

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-1523/
Summaries are generated and may contain mistakes; the official description above is the record.