# CVE-2021-44827: Command injection in n/a

> Remote authenticated attackers can execute arbitrary OS commands with root privileges via the X_TP_ExternalIPv6Address parameter on TP-Link Archer C20i routers.

- **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:** 4 Mar 2022
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-m37g-hc3h-jpg8

## What is CVE-2021-44827?

CVE-2021-44827 is a high-severity command injection vulnerability in n/a, published on 4 Mar 2022. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

There is remote authenticated OS command injection on TP-Link Archer C20i 0.9.1 3.2 v003a.0 Build 170221 Rel.55462n devices vie the X_TP_ExternalIPv6Address HTTP parameter, allowing a remote attacker to run arbitrary commands on the router with root privileges.

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

## Which versions are affected by CVE-2021-44827?

It affects 1 product.


Products: Tp-Link Archer C20i Firmware.

## How do I fix CVE-2021-44827?

No fix has been published for CVE-2021-44827 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-44827 being exploited?

There is no known exploitation of CVE-2021-44827 in the wild and no public exploit code.

Public exploit code:

- A PoC for CVE-2021-44827 - authenticated remote code execution in Tp-link Archer C20i (github_poc): https://github.com/full-disclosure/CVE-2021-44827

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-44827 and fix it if it is affected.

What it is: CVE-2021-44827 is a high-severity command injection vulnerability in n/a, published on 4 Mar 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-2021-44827 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-2021-44827/ (Markdown: https://insights.sbomify.com/CVE-2021-44827/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-44827
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-44827
- OSV: https://osv.dev/vulnerability/CVE-2021-44827

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-44827/
Summaries are generated and may contain mistakes; the official description above is the record.