A €5 domain bought control over military base call routing

A security researcher spent €5 on an expired domain and took over the phone call routing infrastructure for entire island territories.

ENUM (e164.arpa) is a mostly dead 2000s standard designed to route traditional phone calls over the internet using DNS. A security researcher discovered that three country-code zones—covering Saint Helena (+290), Diego Garcia (+246), and Ascension Island (+247)—pointed to an expired nameserver domain. They bought ns.enum.org.uk for €5, instantly gaining full DNS control to intercept or re-route calls meant for those regions.

Why it matters: Old infrastructure rarely gets safely decommissioned; it usually sits around forgotten. A single €5 domain handed over the power to intercept phone routing to sensitive locations like military bases, showing how abandoned telecom bridges leave massive security blind spots.

Know this: ENUM works by reversing a phone number, adding dots between every digit, and appending .e164.arpa. Carriers were supposed to query these NAPTR records to find cheap internet routes (SIP/VoIP) for calls, skipping traditional phone networks entirely.

Next time you decommission a system, make sure you don't leave the keys in the domain registrar.