CVE-2021-43797

Netty is an asynchronous event-driven network application framework for
rapid development of maintainable high performance protocol servers &
clients. Netty prior to version 4.1.71.Final skips control chars when they
are present at the beginning / end of the header name. It should instead
fail fast as these are not allowed by the spec and could lead to HTTP
request smuggling. Failing to do the validation might cause netty to
“sanitize” header names before it forward these to another remote system
when used as proxy. This remote system can’t see the invalid usage anymore,
and therefore does not do the validation itself. Users should upgrade to
version 4.1.71.Final.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1001437&gt;