AIOHTTP vulnerable to denial of service through large payloads

Summary

A request can be crafted in such a way that an aiohttp server's memory fills up uncontrollably during processing.

Impact

If an application includes a handler that uses the Request.post() method, an attacker may be able to freeze the server by exhausting the memory.

Patch: https://github.com/aio-libs/aiohttp/commit/b7dbd35375aedbcd712cbae8ad513d56d11cce60