Fix the DNS Zone: Exposed Internal Host

A company's public DNS zone lists a staging admin host, and the name server hands a full copy of the zone to any host that asks. The staging host was scanned the day after it appeared.

Serve internal names only in the internal view, and allow zone transfers to the secondary server only. The public names must keep resolving, staff must still reach the staging host internally, and the secondary must still copy the zone.

Work through the bench tabs in order. Incident tells you what happened. Target shows the service and lets you use it as an ordinary user would. Fix is where you change the setting that caused the problem; the check table re-runs the platform's own test cases every time you save, and every row marked still works must stay green. Detect asks you to mark the log lines, or write a rule, that catch the misuse without flagging normal traffic. Explain asks a few short questions about why the fix works. When every step passes, Prove releases your flag.

Everything runs in a simulated, in-memory copy of the service built for you alone. The misuse cases are generated by the platform; you never need to write an attack, only the defence.