# GHSA-mmqv-m45h-q2hp: Sandbox Breakout / Arbitrary Code Execution in localeval

> Attackers can execute arbitrary code by bypassing the sandbox in the localeval library via constructor access.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 4 Sep 2020

## What is GHSA-mmqv-m45h-q2hp?

GHSA-mmqv-m45h-q2hp is a code injection vulnerability in localeval, published on 4 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

All versions of `localeval` are vulnerable to Sandbox Escape leading to Remote Code Execution. The package fails to restrict access to the main context through `constructor.constructor`. This may allow attackers to execute arbitrary code in the system.  Evaluating the payload 
```
constructor.constructor("return process.env")()
``` 

returns the contents of `process.env`.

## Recommendation

No fix is currently available. Consider using an alternative package until a fix is made available.

## Which versions are affected by GHSA-mmqv-m45h-q2hp?

2 open source packages ship an affected version, including localeval.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `localeval` | npm | All versions | 15.3.0 |
| `localeval` | npm | All versions | 15.3.0 |

## How do I fix GHSA-mmqv-m45h-q2hp?

Upgrade localeval to 15.3.0 or later.

## Is GHSA-mmqv-m45h-q2hp being exploited?

There is no known exploitation of GHSA-mmqv-m45h-q2hp in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for GHSA-mmqv-m45h-q2hp and fix it if it is affected.

What it is: GHSA-mmqv-m45h-q2hp is a code injection vulnerability in localeval, published on 4 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of GHSA-mmqv-m45h-q2hp in the wild and no public exploit code.

Affected packages and fixed versions:
- localeval (npm): affected all versions; fixed in 15.3.0
- localeval (npm): affected all versions; fixed in 15.3.0

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/GHSA-mmqv-m45h-q2hp/ (Markdown: https://insights.sbomify.com/GHSA-mmqv-m45h-q2hp/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/GHSA-mmqv-m45h-q2hp

---
From sbomify Insights: https://insights.sbomify.com/GHSA-mmqv-m45h-q2hp/
Summaries are generated and may contain mistakes; the official description above is the record.