# brotli bomb PoC

A brotli "decompression bomb": a ~1 MB file on disk that expands to **50 GB** in the browser.
The decompressed payload starts with a real PNG, so the image renders — then the browser keeps
inflating the trailing 50 GB of zeros and runs **out of memory / crashes the tab**.

A gzip version (`bomb.png.gz`) is also built, so clients that don't accept `br` still get bombed.

## Files

| File | What it does |
|------|--------------|
| `image.png` | The real image embedded at the front of the payload (input). |
| `create.py` | Builds the bombs: `[PNG] + 1 MB random + 50 GB zeros` → `bomb.png.br` **and** `bomb.png.gz`. |
| `bomb.png.br` | The brotli bomb (~1 MB on disk, 50 GB decompressed). |
| `bomb.png.gz` | The gzip bomb (~50 MB on disk, 50 GB decompressed) — fallback for clients without `br`. |
| `server.py` | Minimal Flask server. Loads both prebuilt bombs and picks `br` or `gzip` per the client's `Accept-Encoding`. |
| `slow_download.py` | Fuller server: inline `<img>` page + download route. |

## Usage

```sh
python create.py        # build bomb.png.br + bomb.png.gz (pass --rebuild to overwrite)
python server.py        # serve on :8080, then open in a browser
```

> ⚠️ Opening the page makes the browser decompress 50 GB into memory. Expect the tab to hang and crash.