# CVE-2021-47770: OpenPLC 3 - Remote Code Execution

> Authenticated attackers can inject malicious code via the hardware configuration interface in OpenPLC 3 to achieve remote code execution.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 21 Jan 2026
- **Updated:** 14 Aug 2026
- **Also known as:** GHSA-grvf-xrw5-jxhc

## What is CVE-2021-47770?

CVE-2021-47770 is a high-severity code injection vulnerability in Autonomy OpenPLC, published on 21 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

OpenPLC v3 contains an authenticated remote code execution vulnerability that allows attackers with valid credentials to inject malicious code through the hardware configuration interface. Attackers can upload a custom hardware layer with embedded reverse shell code that establishes a network connection to a specified IP and port, enabling remote command execution.

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

## Which versions are affected by CVE-2021-47770?


## How do I fix CVE-2021-47770?

No fix has been published for CVE-2021-47770 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47770 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47770 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47770 and fix it if it is affected.

What it is: CVE-2021-47770 is a high-severity code injection vulnerability in Autonomy OpenPLC, published on 21 Jan 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47770 exists.

Affected product: Autonomy OpenPLC. 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-2021-47770/ (Markdown: https://insights.sbomify.com/CVE-2021-47770/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47770
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47770
- OSV: https://osv.dev/vulnerability/CVE-2021-47770

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47770/
Summaries are generated and may contain mistakes; the official description above is the record.