TokyoWesterns CTF 2020 | writeups by @terjanq Urlcheck v1 (98 points, 160 solves) The goal was to bypass WAF protection to access local resources. app.re_ip = re.compile('\A(\d+)\.(\d+)\.(\d+)\.(\d+)\Z') def valid_ip(ip): matches = app.re_ip.match(ip)