# CVE-2021-31505: Hardcoded credentials in Q Plus

> Attackers with physical access can exploit hard-coded SSH credentials in a special boot mode to execute arbitrary code as root.

- **Severity:** Medium 6.8 (`CVSS:3.0/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:** 29 Jun 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-49rv-vwhv-6vcw

## What is CVE-2021-31505?

CVE-2021-31505 is a medium-severity vulnerability in Arlo Q Plus, published on 29 Jun 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

This vulnerability allows attackers with physical access to escalate privileges on affected installations of Arlo Q Plus 1.9.0.3_278. Authentication is not required to exploit this vulnerability. The specific flaw exists within the SSH service. The device can be booted into a special operation mode where hard-coded credentials are accepted for SSH authentication. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of root. Was ZDI-CAN-12890.

Weakness: CWE-798 (Use of Hard-coded Credentials)

## Which versions are affected by CVE-2021-31505?

It affects 1 product.


Products: Arlo Q Plus Firmware.

## How do I fix CVE-2021-31505?

No fix has been published for CVE-2021-31505 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-31505 being exploited?

There is no known exploitation of CVE-2021-31505 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-31505 and fix it if it is affected.

What it is: CVE-2021-31505 is a medium-severity vulnerability in Arlo Q Plus, published on 29 Jun 2021. 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-2021-31505 in the wild and no public exploit code.

Affected product: Arlo Q 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-2021-31505/ (Markdown: https://insights.sbomify.com/CVE-2021-31505/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-31505
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-31505
- OSV: https://osv.dev/vulnerability/CVE-2021-31505

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-31505/
Summaries are generated and may contain mistakes; the official description above is the record.