Bouncer — DalCTF 2026

A read-only anonymous FTP gateway turns out to be a Redis health-check proxy; abusing the PORT command for an FTP bounce plus a newline-smuggled RETR inline command yields a bidirectional Redis relay that scans the subnet and reads the flag.

June 7, 2026 · 10 min · 2096 words · Th3B0yWh0L1v3d