CVE-2020-25109: Ethernut Nut/os

Critical severity, CVSS 9.8. EPSS: 53.7% chance of exploitation in the next 30 days.

An issue was discovered in the DNS implementation in Ethernut in Nut/OS 5.1. The number of DNS queries/responses (set in a DNS header) is not checked against the data present. This may lead to successful Denial-of-Service, and possibly Remote Code Execution.

Affected products

• Ethernut Nut/os: up to and including 5.1

Published 2020-12-11. Last modified 2026-06-17.