# CVE-2021-21941: Use after free in Anker

> A use-after-free flaw in Anker Eufy Homebase 2 allows remote attackers to execute arbitrary code via crafted network packets.

- **Severity:** Critical 10.0 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 12 Oct 2021
- **Updated:** 3 Aug 2024
- **Also known as:** GHSA-8fwh-83cj-r97c

## What is CVE-2021-21941?

CVE-2021-21941 is a critical use after free vulnerability in Anker, published on 12 Oct 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A use-after-free vulnerability exists in the pushMuxer CreatePushThread functionality of Anker Eufy Homebase 2 2.1.6.9h. A specially-crafted set of network packets can lead to remote code execution.

Weakness: CWE-416 (Use After Free), CWE-368 (Context Switching Race Condition)

## Which versions are affected by CVE-2021-21941?

It affects 1 product.


Products: Anker Eufy Homebase 2 Firmware.

## How do I fix CVE-2021-21941?

No fix has been published for CVE-2021-21941 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-21941 being exploited?

There is no known exploitation of CVE-2021-21941 in the wild and no public exploit code.

## Other vulnerabilities in Anker

- [CVE-2022-21806](https://insights.sbomify.com/CVE-2022-21806/): Use after free in Eufy Homebase 2 (critical 10.0)
- [CVE-2021-21950](https://insights.sbomify.com/CVE-2021-21950/): Memory corruption in Anker (critical 10.0)
- [CVE-2021-21951](https://insights.sbomify.com/CVE-2021-21951/): Memory corruption in Anker (critical 10.0)
- [CVE-2021-21940](https://insights.sbomify.com/CVE-2021-21940/): Memory corruption in Anker (critical 10.0)
- [CVE-2021-21954](https://insights.sbomify.com/CVE-2021-21954/): Command injection in Anker (critical 9.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-21941 and fix it if it is affected.

What it is: CVE-2021-21941 is a critical use after free vulnerability in Anker, published on 12 Oct 2021. 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-2021-21941 in the wild and no public exploit code.

Affected product: Anker. 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-2021-21941/ (Markdown: https://insights.sbomify.com/CVE-2021-21941/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-21941
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-21941
- OSV: https://osv.dev/vulnerability/CVE-2021-21941

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-21941/
Summaries are generated and may contain mistakes; the official description above is the record.