# CVE-2020-18331: Path traversal in n/a

> Attackers can exploit a directory traversal flaw in the ChinaMobile PLC Wireless Router to read arbitrary files via the getpage parameter.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Jan 2023
- **Updated:** 1 Apr 2025
- **Also known as:** GHSA-w48q-2q3f-h2f8

## What is CVE-2020-18331?

CVE-2020-18331 is a critical path traversal vulnerability in n/a, published on 25 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Directory traversal vulnerability in ChinaMobile PLC Wireless Router model GPN2.4P21-C-CN running the firmware version W2000EN-01(hardware platform Gpn2.4P21-C_WIFI-V0.05), via the getpage parameter to /cgi-bin/webproc.

Weakness: CWE-22 (Improper Limitation of a Pathname to a Restricted Directory)

## Which versions are affected by CVE-2020-18331?

It affects 1 product.


Products: Chinamobileltd Gpn2.4p21-C-Cn Firmware.

## How do I fix CVE-2020-18331?

No fix has been published for CVE-2020-18331 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-18331 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-18331 exists.

## Other vulnerabilities in n/a

- [CVE-2020-18330](https://insights.sbomify.com/CVE-2020-18330/): Path traversal in n/a (critical 9.1)
- [CVE-2019-6279](https://insights.sbomify.com/CVE-2019-6279/): Missing authorization in n/a (high 8.8)
- [CVE-2019-6282](https://insights.sbomify.com/CVE-2019-6282/): Cross-site request forgery in n/a (high 8.8)
- [CVE-2019-1010136](https://insights.sbomify.com/CVE-2019-1010136/): Missing authorization in GPN2.4P21-C-CN (high 7.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-18331 and fix it if it is affected.

What it is: CVE-2020-18331 is a critical path traversal vulnerability in n/a, published on 25 Jan 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-18331 exists.

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-2020-18331/ (Markdown: https://insights.sbomify.com/CVE-2020-18331/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-18331
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-18331
- OSV: https://osv.dev/vulnerability/CVE-2020-18331

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-18331/
Summaries are generated and may contain mistakes; the official description above is the record.