# CVE-2021-31630: Command injection in n/a

> Remote attackers can execute arbitrary code via the Hardware Layer Code Box component in Open PLC Webserver v3.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/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:** 3 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-2c27-grr5-3w2g

## What is CVE-2021-31630?

CVE-2021-31630 is a high-severity command injection vulnerability in n/a, published on 3 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Command Injection in Open PLC Webserver v3 allows remote attackers to execute arbitrary code via the "Hardware Layer Code Box" component on the "/hardware" page of the application.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2021-31630?

It affects 1 product.


Products: Openplcproject Openplc V3 Firmware.

## How do I fix CVE-2021-31630?

No fix has been published for CVE-2021-31630 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31630 being exploited?

There is no known exploitation of CVE-2021-31630 in the wild and no public exploit code.

Public exploit code:

- Python script for exploiting command injection in Open PLC Webserver v3 (github_poc): https://github.com/thewhiteh4t/cve-2021-31630
- proof of Concept (PoC) exploit for CVE-2021-31630, targeting the OpenPLC service running on the WifineticTwo box on the Hack The Box platform. (github_poc): https://github.com/Hunt3r0x/CVE-2021-31630-HTB
- https://github.com/machevalia/OpenPLC-CVE-2021-31630-RCE (github_poc): https://github.com/machevalia/OpenPLC-CVE-2021-31630-RCE
- Exploit for Authenticated Remote Code Execution on OpenPLC v3 Webserver (github_poc): https://github.com/hev0x/CVE-2021-31630-OpenPLC_RCE
- This is a automation of cve-2021-31630 exploitation (github_poc): https://github.com/adibna/cve-2021-31630
- A simple python script to exploit CVE-2021-31630 on HTB WifineticTwo CTF (github_poc): https://github.com/behindsecurity/htb-wifinetictwo-exploit

## Other vulnerabilities in n/a

- [CVE-2026-28205](https://insights.sbomify.com/CVE-2026-28205/): Initialization of a resource with an insecure default in OpenPLC_V3 (critical 9.2)
- [CVE-2026-35556](https://insights.sbomify.com/CVE-2026-35556/): Plaintext storage of a password in OpenPLC_V3 (critical 9.2)
- [CVE-2024-34026](https://insights.sbomify.com/CVE-2024-34026/): Memory corruption in OpenPLC v3 (critical 9.0)
- [CVE-2026-35063](https://insights.sbomify.com/CVE-2026-35063/): Missing Authorization in OpenPLC_V3 (high 8.7)
- [CVE-2024-36980](https://insights.sbomify.com/CVE-2024-36980/): Denial of service in OpenPLC v3 (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31630 and fix it if it is affected.

What it is: CVE-2021-31630 is a high-severity command injection vulnerability in n/a, published on 3 Aug 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-31630 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-2021-31630/ (Markdown: https://insights.sbomify.com/CVE-2021-31630/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31630
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31630
- OSV: https://osv.dev/vulnerability/CVE-2021-31630

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31630/
Summaries are generated and may contain mistakes; the official description above is the record.