Ringtrue

CACTF2026

Task: not-stripped x86-64 ELF implements a quantized int8 MLP (8-8-8-8) whose output is checked for exact integer equality against an embedded reference signature; all weights/biases live readably in .data. Solution: extract parameters, model the piecewise-linear network in z3 to invert the input ('SaltCrwn'), then reproduce the SHA-256 keystream XOR to decrypt the sealed flag.