# CVE-2020-6879: Missing authorization in ZXHN F670L

> Attackers can bypass front-end restrictions to tamper with static routing parameters on ZTE routers by sending crafted POST requests to the backend.

- **Severity:** Low 3.5 (`CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3jm3-wf93-rc5x

## What is CVE-2020-6879?

CVE-2020-6879 is a low-severity missing authorization vulnerability in ZXHN F670L, published on 19 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Some ZTE devices have input verification vulnerabilities. The devices support configuring a static prefix through the web management page. The restriction of the front-end code can be bypassed by constructing a POST request message and sending the request to the creation of a static routing rule configuration interface. The WEB service backend fails to effectively verify the abnormal input. As a result, the attacker can successfully use the vulnerability to tamper parameter values. This affects: ZXHN Z500 V1.0.0.2B1.1000 and ZXHN F670L V1.1.10P1N2E. This is fixed in ZXHN Z500 V1.0.1.1B1.1000 and ZXHN F670L V1.1.10P2N2.

Weakness: CWE-20 (Improper Input Validation)

## Which versions are affected by CVE-2020-6879?

It affects 2 products.


Products: Zte Zxhn F670l Firmware, Zte Zxhn Z500 Firmware.

## How do I fix CVE-2020-6879?

No fix has been published for CVE-2020-6879 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-6879 being exploited?

There is no known exploitation of CVE-2020-6879 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-6879 and fix it if it is affected.

What it is: CVE-2020-6879 is a low-severity missing authorization vulnerability in ZXHN F670L, published on 19 Nov 2020. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2020-6879 in the wild and no public exploit code.

Affected product: ZXHN F670L. 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-2020-6879/ (Markdown: https://insights.sbomify.com/CVE-2020-6879/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-6879
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-6879
- OSV: https://osv.dev/vulnerability/CVE-2020-6879

---
From sbomify Insights: https://insights.sbomify.com/CVE-2020-6879/
Summaries are generated and may contain mistakes; the official description above is the record.