CVE-2021-21409

Name	CVE-2021-21409
Description	Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. In Netty (io.netty:netty-codec-http2) before version 4.1.61.Final there is a vulnerability that enables request smuggling. The content-length header is not correctly validated if the request only uses a single Http2HeaderFrame with the endStream set to to true. This could lead to request smuggling if the request is proxied to a remote peer and translated to HTTP/1.1. This is a followup of GHSA-wm47-8v5p-wjpj/CVE-2021-21295 which did miss to fix this one case. This was fixed as part of 4.1.61.Final.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)
References	DSA-4885-1
Debian Bugs	986217

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
netty (PTS)	buster	1:4.1.33-1+deb10u2	fixed
	buster (security)	1:4.1.33-1+deb10u3	fixed
	bullseye (security), bullseye	1:4.1.48-4+deb11u1	fixed
	bookworm, sid	1:4.1.48-7	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
netty	source	buster	1:4.1.33-1+deb10u2		DSA-4885-1
netty	source	(unstable)	1:4.1.48-4			986217

Notes

[stretch] - netty <ignored> (Minor issue, fix requires major changes of HTTP2 module)
Fixed by: https://github.com/netty/netty/commit/b0fa4d5aab4215f3c22ce6123dd8dd5f38dc0432
https://github.com/netty/netty/security/advisories/GHSA-f256-j965-7f32
Is a followup to: https://github.com/netty/netty/security/advisories/GHSA-wm47-8v5p-wjpj