The author discovered that port 0, traditionally avoided by tools and scanners, can actually be used for network communication since TCP headers accept it as a valid destination. After scanning the entire IPv4 space for port 0 listeners, they found several unexpected services, including their own IRC network, revealing hidden attack surface on the internet.
Background
Port 0 is conventionally reserved and skipped by scanning tools, making it an overlooked area of the TCP/IP port space. This research highlights gaps in conventional network security assumptions.
- Source
- Lobsters
- Published
- Nov 7, 2026 at 07:03 AM
- Score
- 7.0 / 10