# CVE-2020-8157: Auth bypass in UniFi Cloud Key Gen2, Cloud Key Gen2 plus

> Attackers with physical access can gain unrestricted root privileges via the serial interface on UniFi Cloud Key devices.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:P/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:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 May 2020
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-3qh5-7339-m5xf

## What is CVE-2020-8157?

CVE-2020-8157 is a medium-severity authentication bypass vulnerability in UniFi Cloud Key Gen2, Cloud Key Gen2 plus, published on 2 May 2020. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

UniFi Cloud Key firmware <= v1.1.10 for Cloud Key gen2 and Cloud Key gen2 Plus contains a vulnerability that allows unrestricted root access through the serial interface (UART).

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2020-8157?

It affects 2 products.


Products: Ui Unifi Cloud Key Gen2 Firmware, Ui Unifi Cloud Key Gen2 Plus Firmware.

## How do I fix CVE-2020-8157?

No fix has been published for CVE-2020-8157 yet. Limit exposure of the affected software until one is available.

## Is CVE-2020-8157 being exploited?

There is no known exploitation of CVE-2020-8157 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2020-8157 and fix it if it is affected.

What it is: CVE-2020-8157 is a medium-severity authentication bypass vulnerability in UniFi Cloud Key Gen2, Cloud Key Gen2 plus, published on 2 May 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-2020-8157 in the wild and no public exploit code.

Affected product: UniFi Cloud Key Gen2, Cloud Key Gen2 plus. 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-2020-8157/ (Markdown: https://insights.sbomify.com/CVE-2020-8157/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2020-8157
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-8157
- OSV: https://osv.dev/vulnerability/CVE-2020-8157

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From sbomify Insights: https://insights.sbomify.com/CVE-2020-8157/
Summaries are generated and may contain mistakes; the official description above is the record.