# CVE-2021-31698: Command injection in n/a

> Remote attackers can execute arbitrary code on Quectel EG25-G devices by injecting shell metacharacters into AT command inputs.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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:** 12 Aug 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-7r3r-jp3h-r9vx

## What is CVE-2021-31698?

CVE-2021-31698 is a critical command injection vulnerability in n/a, published on 12 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Quectel EG25-G devices through 202006130814 allow executing arbitrary code remotely by using an AT command to place shell metacharacters in quectel_handle_fumo_cfg input in atfwd_daemon.

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

## Which versions are affected by CVE-2021-31698?

It affects 1 product.


Products: Quectel Eg25-G Firmware.

## How do I fix CVE-2021-31698?

No fix has been published for CVE-2021-31698 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31698 being exploited?

There is no known exploitation of CVE-2021-31698 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31698 and fix it if it is affected.

What it is: CVE-2021-31698 is a critical command injection vulnerability in n/a, published on 12 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-31698 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-2021-31698/ (Markdown: https://insights.sbomify.com/CVE-2021-31698/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31698
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31698
- OSV: https://osv.dev/vulnerability/CVE-2021-31698

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31698/
Summaries are generated and may contain mistakes; the official description above is the record.