# CVE-2020-36963: Intelbras Router RF 301K 1.1.2 - Authentication Bypass

> Unauthenticated attackers can download sensitive router configuration files via a specific HTTP request, exposing network settings.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 28 Jan 2026
- **Updated:** 28 Jul 2026
- **Also known as:** GHSA-mgpr-67wh-564q

## What is CVE-2020-36963?

CVE-2020-36963 is a high-severity authentication bypass vulnerability in Intelbras Router RF 301K, published on 28 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Intelbras Router RF 301K firmware version 1.1.2 contains an authentication bypass vulnerability that allows unauthenticated attackers to download router configuration files. Attackers can send a specific HTTP GET request to /cgi-bin/DownloadCfg/RouterCfm.cfg to retrieve sensitive router configuration without authentication.

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

## Which versions are affected by CVE-2020-36963?


## How do I fix CVE-2020-36963?

No fix has been published for CVE-2020-36963 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-36963 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2020-36963 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-36963 and fix it if it is affected.

What it is: CVE-2020-36963 is a high-severity authentication bypass vulnerability in Intelbras Router RF 301K, published on 28 Jan 2026. 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-2020-36963 exists.

Affected product: Intelbras Router RF 301K. 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-2020-36963/ (Markdown: https://insights.sbomify.com/CVE-2020-36963/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-36963
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-36963
- OSV: https://osv.dev/vulnerability/CVE-2020-36963

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-36963/
Summaries are generated and may contain mistakes; the official description above is the record.