TokyoWesterns CTF 6th 2020 Writeup

urlcheck v1 (Web, 98 points) Solved by Ozetta. Objective: SSRF http://127.0.0.1/admin-status The input needs to fulfil the pattern '\A(\d+)\.(\d+)\.(\d+)\.(\d+)\Z' and the first octet cannot be 0 or 127, and some other patterns for internal IP addresses. For some reason, int("0177") is still 177 instead of 127 in Python, so we can use http://0177.0.0.1/admin-status urlcheck v2 (Web, 128 points) Solved by Ozetta. Objective: SSRF http://localhost/admin-status Standard TOCTOU bug, just use DNS rebinding to get access: http://23bbd91c....

October 9, 2020 ยท cire meat pop, harrier, Ozetta, Mystiz