# CVE-2018-1164: Missing authorization in ZyXEL P-870H-51 DSL Router

> Remote attackers can reboot ZyXEL DSL routers and access critical functions without authentication due to improper access controls on CGI endpoints.

- **Severity:** Critical 9.8 (`CVSS:3.0/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:** 21 Feb 2018
- **Updated:** 5 Aug 2024
- **Also known as:** GHSA-943g-cpqh-7wmv

## What is CVE-2018-1164?

CVE-2018-1164 is a critical missing authorization vulnerability in ZyXEL P-870H-51 DSL Router, published on 21 Feb 2018. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

This vulnerability allows remote attackers to cause a denial-of-service condition on vulnerable installations of ZyXEL P-870H-51 DSL Router 1.00(AWG.3)D5. Authentication is not required to exploit this vulnerability. The specific flaw exists within numerous exposed CGI endpoints. The vulnerability is caused by improper access controls that allow access to critical functions without authentication. An attacker can use this vulnerability to reboot affected devices, along with other actions. Was ZDI-CAN-4540.

Weakness: CWE-732 (Incorrect Permission Assignment for Critical Resource), CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2018-1164?

It affects 1 product.


Products: Zyxel P-870h-51 Firmware.

## How do I fix CVE-2018-1164?

No fix has been published for CVE-2018-1164 yet. Limit exposure of the affected software until one is available.

## Is CVE-2018-1164 being exploited?

There is no known exploitation of CVE-2018-1164 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2018-1164 and fix it if it is affected.

What it is: CVE-2018-1164 is a critical missing authorization vulnerability in ZyXEL P-870H-51 DSL Router, published on 21 Feb 2018. 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-2018-1164 in the wild and no public exploit code.

Affected product: ZyXEL P-870H-51 DSL Router. 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-2018-1164/ (Markdown: https://insights.sbomify.com/CVE-2018-1164/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2018-1164
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2018-1164
- OSV: https://osv.dev/vulnerability/CVE-2018-1164

---
From sbomify Insights: https://insights.sbomify.com/CVE-2018-1164/
Summaries are generated and may contain mistakes; the official description above is the record.