hacnho/protobuf-contextrule-allowed-request-extensions-dos-poc

Protocol Buffers ContextRule allowed_request_extensions materialization DoS PoC

This repository contains a benign security research PoC for a protobuf binary artifact that drives large repeated-string materialization during google.api.context_pb2.ContextRule.ParseFromString(...).

Files:

• control_one_selector.pb
• malicious_allowed_request_extensions_5000000.pb
• reproduce.py

Observed behavior:

• control artifact:
  • parses successfully with zero allowed_request_extensions
• malicious artifact:
  • both files are 10,000,000 bytes
  • parses successfully with 5,000,000 allowed_request_extensions entries
  • increases peak RSS by about 200000 kB in local clean-process replay
  • takes about 14.56x the control parse time

Tested runtime:

• protobuf==7.35.1
• Python: /usr/bin/python3

Public files:

• https://huggingface.co/hacnho/protobuf-contextrule-allowed-request-extensions-dos-poc/resolve/main/control_one_selector.pb
• https://huggingface.co/hacnho/protobuf-contextrule-allowed-request-extensions-dos-poc/resolve/main/malicious_allowed_request_extensions_5000000.pb
• https://huggingface.co/hacnho/protobuf-contextrule-allowed-request-extensions-dos-poc/resolve/main/reproduce.py

Reproduction:

python3 reproduce.py