# CVE-2021-44527: Denial of service in UniFi Switches

> A network-accessible attacker can cause a Denial of Service on UniFi Switches, requiring a firmware upgrade to mitigate.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:** 7 Dec 2021
- **Updated:** 4 Aug 2024
- **Also known as:** GHSA-2fpq-jhjc-vqfv

## What is CVE-2021-44527?

CVE-2021-44527 is a medium-severity denial of service vulnerability in UniFi Switches, published on 7 Dec 2021. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability found in UniFi Switch firmware Version 5.43.35 and earlier allows a malicious actor who has already gained access to the network to perform a Deny of Service (DoS) attack on the affected switch.This vulnerability is fixed in UniFi Switch firmware 5.76.6 and later.

Weakness: CWE-400 (Uncontrolled Resource Consumption)

## Which versions are affected by CVE-2021-44527?

It affects 1 product.


Products: Ui Unifi Switch Firmware.

## How do I fix CVE-2021-44527?

No fix has been published for CVE-2021-44527 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-44527 being exploited?

There is no known exploitation of CVE-2021-44527 in the wild and no public exploit code.

## Other vulnerabilities in UniFi Switches

- [CVE-2023-35085](https://insights.sbomify.com/CVE-2023-35085/): Integer overflow in UniFi Access Points (critical 9.0)
- [CVE-2023-38034](https://insights.sbomify.com/CVE-2023-38034/): Command injection in UniFi Access Points (high 8.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-44527 and fix it if it is affected.

What it is: CVE-2021-44527 is a medium-severity denial of service vulnerability in UniFi Switches, published on 7 Dec 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-2021-44527 in the wild and no public exploit code.

Affected product: UniFi Switches. 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-2021-44527/ (Markdown: https://insights.sbomify.com/CVE-2021-44527/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-44527
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-44527
- OSV: https://osv.dev/vulnerability/CVE-2021-44527

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-44527/
Summaries are generated and may contain mistakes; the official description above is the record.