Some 300,000 IPs vulnerable to this Loop DoS attack

The report describes the disclosure of a trivial but impactful Loop Denial-of-Service (Loop DoS) technique that uses source-spoofed UDP error messages to induce infinite mutual error-response storms between vulnerable services (TFTP, DNS, NTP and legacy protocols like Echo, Chargen, QOTD). Researchers at CISPA released details and scanning code, coordinated disclosure with vendors and Shadowserver, and identified numerous affected products (including vendors tied to CVE-2024-1309) and an estimated ~300,000 potentially vulnerable public-facing systems worldwide.