# CVE-2021-47667: Command injection in ZendTo

> Unauthenticated attackers can execute arbitrary commands via shell metacharacters in the tmp_name parameter during file dropoff.

- **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:** No
- **Published:** 5 Apr 2025
- **Updated:** 7 Apr 2025
- **Also known as:** GHSA-r4mc-p68x-wx22

## What is CVE-2021-47667?

CVE-2021-47667 is a critical command injection vulnerability in ZendTo, published on 5 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

An OS command injection vulnerability in lib/NSSDropoff.php in ZendTo 5.24-3 through 6.x before 6.10-7 allows unauthenticated remote attackers to execute arbitrary commands via shell metacharacters in the tmp_name parameter when dropping off a file via a POST /dropoff request.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command)

## Which versions are affected by CVE-2021-47667?


## How do I fix CVE-2021-47667?

No fix has been published for CVE-2021-47667 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47667 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47667 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47667 and fix it if it is affected.

What it is: CVE-2021-47667 is a critical command injection vulnerability in ZendTo, published on 5 Apr 2025. 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-2021-47667 exists.

Affected product: ZendTo. 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-2021-47667/ (Markdown: https://insights.sbomify.com/CVE-2021-47667/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47667
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47667
- OSV: https://osv.dev/vulnerability/CVE-2021-47667

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47667/
Summaries are generated and may contain mistakes; the official description above is the record.