# CVE-2021-42952: Code injection in n/a

> Attackers can escape the sandbox via remote code execution to access internal assets and cloud metadata services.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Feb 2022
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-hcwg-7735-m472

## What is CVE-2021-42952?

CVE-2021-42952 is a critical code injection vulnerability in n/a, published on 25 Feb 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Zepl Notebooks before 2021-10-25 are affected by a sandbox escape vulnerability. Upon launching Remote Code Execution from the Notebook, users can then use that to subsequently escape the running context sandbox and proceed to access internal Zepl assets including cloud metadata services.

## Which versions are affected by CVE-2021-42952?

It affects 1 product.


Products: Zepl Zepl.

## How do I fix CVE-2021-42952?

No fix has been published for CVE-2021-42952 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42952 being exploited?

There is no known exploitation of CVE-2021-42952 in the wild and no public exploit code.

## Other vulnerabilities in n/a

- [CVE-2021-42950](https://insights.sbomify.com/CVE-2021-42950/): Code injection in n/a (high 8.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42952 and fix it if it is affected.

What it is: CVE-2021-42952 is a critical code injection vulnerability in n/a, published on 25 Feb 2022. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-42952 in the wild and no public exploit code.

Affected product: n/a. 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-2021-42952/ (Markdown: https://insights.sbomify.com/CVE-2021-42952/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42952
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42952
- OSV: https://osv.dev/vulnerability/CVE-2021-42952

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42952/
Summaries are generated and may contain mistakes; the official description above is the record.