UofTCTF 2026 – Firewall
Challenge Overview This CTF challenge presents an eBPF-based network firewall that filters TCP traffic for the keyword “flag” and the character ‘%’. The objective is to retrieve a flag from an nginx web server at 35.227.38.232:5000 serving /flag.html. Vulnerability Analysis Firewall Implementation The firewall is implemented as an eBPF program (firewall.c) attached to both ingress and egress TC … Read more