# CVE-2020-29138: Missing authorization in n/a

> Remote unauthenticated users can download router configuration files via a specific URI if a valid session is active, exposing sensitive settings.

- **Severity:** Medium 5.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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:** 27 Nov 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-mhcx-4c5f-w275

## What is CVE-2020-29138?

CVE-2020-29138 is a medium-severity missing authorization vulnerability in n/a, published on 27 Nov 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Incorrect Access Control in the configuration backup path in SAGEMCOM F@ST3486 NET DOCSIS 3.0, software NET_4.109.0, allows remote unauthenticated users to download the router configuration file via the /backupsettings.conf URI, when any valid session is running.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2020-29138?

It affects 1 product.


Products: Sagemcom F\@st 3486 Router Firmware.

## How do I fix CVE-2020-29138?

No fix has been published for CVE-2020-29138 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-29138 being exploited?

There is no known exploitation of CVE-2020-29138 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-29138 and fix it if it is affected.

What it is: CVE-2020-29138 is a medium-severity missing authorization vulnerability in n/a, published on 27 Nov 2020. 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-2020-29138 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-2020-29138/ (Markdown: https://insights.sbomify.com/CVE-2020-29138/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-29138
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-29138
- OSV: https://osv.dev/vulnerability/CVE-2020-29138

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-29138/
Summaries are generated and may contain mistakes; the official description above is the record.