conduit-hyper vulnerable to Denial of Service from unchecked request length

Prior to version 0.4.2, conduit-hyper did not check any limit on a request’s length before calling hyper::body::to_bytes. An attacker could send a malicious request with an abnormally large Content-Length, which could lead to a panic if memory allocation failed for that request.

In version 0.4.2, conduit-hyper sets an internal limit of 128 MiB per request, otherwise returning status 400 (“Bad Request”).

This crate is part of the implementation of Rust’s crates.io, but that service is not affected due to its existing cloud infrastructure, which already drops such malicious requests. Even with the new limit in place, conduit-hyper is not recommended for production use, nor to directly serve the public Internet.

The vulnerability was discovered by Ori Hollander from the JFrog Security Research team.