AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)

Summary

An out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response.

Impact

An attacker controlled server, or possibly an accidental response could trigger a DoS in the client.

Workaround

If unable to upgrade, the Python parser is unaffected and can be used with AIOHTTP_NO_EXTENSIONS=1.

Patch: https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d