---
tags:
  - security
  - proof-of-concept
  - protobuf
license: mit
---

# Protocol Buffers Struct fields materialization DoS PoC

This repository contains a benign security research PoC for a `.pb` artifact
that drives repeated map-entry materialization during
`struct_pb2.Struct.ParseFromString(...)`.

Files:

- `control_one_struct_field.pb`
- `malicious_struct_fields_1000000.pb`
- `reproduce.py`

Observed behavior:

- control artifact:
  - parses successfully with one struct field
- malicious artifact:
  - parses successfully with `1,000,000` struct fields
  - materially increases peak RSS during normal parse

Tested runtime:

```bash
python3 -m pip install protobuf==7.35.1
```