PoC: BINUNICODE8 Signed/Unsigned Length Confusion in JIT Unpickler
Vulnerability: unpickler.cpp:344 reads BINUNICODE8 length as int64_t (signed) instead of uint64_t. The implicit conversion to size_t in readBytes() causes 32-bit truncation on ARM mobile (pickle desync → corruption) and DoS on 64-bit (excessive allocation).
Files
poc_binunicode8_overflow.py— Full PoC with code analysis, 64-bit DoS demo, 32-bit truncation testtest_truncation.cpp— Standalone C++ 32-bit truncation demonstration
Quick Start
pip install torch
python poc_binunicode8_overflow.py
Expected Output
- Part 1: Code analysis showing int64_t vs uint64_t mismatch
- Part 2: 64-bit DoS (MemoryError, end of archive, max_size rejection)
- Part 3: 32-bit truncation table (C++ test)
- Part 4: Pickle stream desync analysis on 32-bit ARM