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

# Protocol Buffers Value struct_value.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.Value.ParseFromString(...)`.

Files:

- `control_one_struct_value.pb`
- `malicious_struct_value_fields_1400000.pb`
- `reproduce.py`

Observed behavior:

- control artifact:
  - parses successfully with one `struct_value` field
- malicious artifact:
  - parses successfully with `1,400,000` nested struct fields
  - materially increases peak RSS during normal parse

Tested runtime:

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