The vulnerability stemmed from insufficient memory safety checks in JIT constant handling and argument validation. Key issues included: 1) Lack of proper constant blinding in Security.cpp allowing memory layout inference, 2) Missing bounds checks in Asm.js argument handling, and 3) Inconsistent validation of constant tables. The commit 2500e1c specifically hardened these areas by adding AssertOrFailFast checks, constant size validation (UInt32Math::AddMul), and improved operand encoding - indicating these were the vulnerable points prior to patching.