# CVE-2021-42912: Command injection in n/a

> Authenticated attackers can execute arbitrary OS commands as root via the ping diagnostic tool in FiberHome ONU GPON devices.

- **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:** 16 Dec 2021
- **Updated:** 9 Jul 2026
- **Also known as:** GHSA-hcfv-5p8h-vvh5

## What is CVE-2021-42912?

CVE-2021-42912 is a high-severity command injection vulnerability in n/a, published on 16 Dec 2021. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

FiberHome ONU GPON AN5506-04-F RP2617 is affected by an OS command injection vulnerability. This vulnerability allows the attacker, once logged in, to send commands to the operating system as the root user via the ping diagnostic tool, bypassing the IP address field, and concatenating OS commands with a semicolon.

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

## Which versions are affected by CVE-2021-42912?

It affects 6 products.


Products: Fiberhome Aan5506-04-G2g Firmware, Fiberhome An5506-01-a Firmware, Fiberhome An5506-01-B Firmware, Fiberhome An5506-02-B Firmware, Fiberhome An5506-04-B Firmware, Fiberhome An5506-04-F Firmware.

## How do I fix CVE-2021-42912?

No fix has been published for CVE-2021-42912 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-42912 being exploited?

There is no known exploitation of CVE-2021-42912 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-42912 and fix it if it is affected.

What it is: CVE-2021-42912 is a high-severity command injection vulnerability in n/a, published on 16 Dec 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-2021-42912 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-2021-42912/ (Markdown: https://insights.sbomify.com/CVE-2021-42912/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-42912
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-42912
- OSV: https://osv.dev/vulnerability/CVE-2021-42912

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-42912/
Summaries are generated and may contain mistakes; the official description above is the record.