WASM-Injection-Framework

A deterministic WebAssembly runtime fuzzing harness built with Go and WasmEdge.

Features

• Deterministic execution — No concurrency, no randomness
• Structured error classification — Failures categorized by stage (load, validate, instantiate, execute)
• Panic-safe — All errors are recovered and reported
• JSON output — Structured results for easy parsing and analysis

Requirements

• Go 1.21+
• WasmEdge runtime installed
• WasmEdge Go SDK

Installation

Install WasmEdge

curl -sSf https://raw.githubusercontent.com/WasmEdge/WasmEdge/master/utils/install.sh | bash
source ~/.wasmedge/env

Build the fuzzer

go mod tidy
go build -o wasm-fuzzer .

Usage

./wasm-fuzzer <directory-with-wasm-files>

Example

./wasm-fuzzer ./testcases

Output Format

The fuzzer outputs structured JSON to stdout:

{
  "total_files": 3,
  "passed": 1,
  "failed": 2,
  "results": [
    {
      "file_path": "./testcases/valid.wasm",
      "file_name": "valid.wasm",
      "success": true,
      "failure_stage": "none",
      "return_values": [42]
    },
    {
      "file_path": "./testcases/invalid.wasm",
      "file_name": "invalid.wasm",
      "success": false,
      "failure_stage": "validate",
      "error_message": "validation failed: invalid module"
    }
  ],
  "failure_counts": {
    "load": 0,
    "validate": 1,
    "instantiate": 0,
    "execute": 1
  }
}

Failure Stages

Stage	Description
load	Failed to read/parse the WASM binary
validate	WASM module failed validation
instantiate	Failed to create module instance
execute	Function "process" not found or execution failed

WASM Module Requirements

Your WASM modules should export a function named process that accepts an i32 parameter:

(module
  (func $process (export "process") (param i32) (result i32)
    local.get 0
    i32.const 1
    i32.add
  )
)

License

MIT