# CVE-2021-27289: Other in n/a

> Attackers can inject spoofed commands via replay attacks in Zigbee devices, triggering false alerts and bypassing authentication mechanisms.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/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:** 15 Apr 2025
- **Updated:** 16 Apr 2025
- **Also known as:** GHSA-25fv-45mr-wm5r

## What is CVE-2021-27289?

CVE-2021-27289 is a critical vulnerability in n/a, published on 15 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A replay attack vulnerability was discovered in a Zigbee smart home kit manufactured by Ksix (Zigbee Gateway Module = v1.0.3, Door Sensor = v1.0.7, Motion Sensor = v1.0.12), where the Zigbee anti-replay mechanism - based on the frame counter field - is improperly implemented. As a result, an attacker within wireless range can resend captured packets with a higher sequence number, which the devices incorrectly accept as legitimate messages. This allows spoofed commands to be injected without authentication, triggering false alerts and misleading the user through notifications in the mobile application used to monitor the network.

Weakness: CWE-294 (Authentication Bypass by Capture-replay)

## Which versions are affected by CVE-2021-27289?


## How do I fix CVE-2021-27289?

No fix has been published for CVE-2021-27289 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-27289 being exploited?

There is no known exploitation of CVE-2021-27289 in the wild and no public exploit code.

Public exploit code:

- CVE-2021-27289: Playback Protection Bypass on Ksix Zigbee devices (github_poc): https://github.com/TheMalwareGuardian/CVE-2021-27289

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-27289 and fix it if it is affected.

What it is: CVE-2021-27289 is a critical vulnerability in n/a, published on 15 Apr 2025. 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-2021-27289 in the wild and no public exploit code.

Affected product: n/a. 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-2021-27289/ (Markdown: https://insights.sbomify.com/CVE-2021-27289/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-27289
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-27289
- OSV: https://osv.dev/vulnerability/CVE-2021-27289

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-27289/
Summaries are generated and may contain mistakes; the official description above is the record.