CVE-2023-34462

Name	CVE-2023-34462
Description	Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. The `SniHandler` can allocate up to 16MB of heap for each channel during the TLS handshake. When the handler or the channel does not have an idle timeout, it can be used to make a TCP server using the `SniHandler` to allocate 16MB of heap. The `SniHandler` class is a handler that waits for the TLS handshake to configure a `SslHandler` according to the indicated server name by the `ClientHello` record. For this matter it allocates a `ByteBuf` using the value defined in the `ClientHello` record. Normally the value of the packet should be smaller than the handshake packet but there are not checks done here and the way the code is written, it is possible to craft a packet that makes the `SslClientHelloHandler`. This vulnerability has been fixed in version 4.1.94.Final.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-5558-1
Debian Bugs	1038947

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+deb10u4	fixed
	bullseye (security), bullseye	1:4.1.48-4+deb11u2	fixed
	bookworm, bookworm (security)	1:4.1.48-7+deb12u1	fixed
	sid, trixie	1:4.1.48-9	fixed

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

Package	Type	Release	Fixed Version	Origin	Debian Bugs
netty	source	buster	(not affected)
netty	source	bullseye	1:4.1.48-4+deb11u2	DSA-5558-1
netty	source	bookworm	1:4.1.48-7+deb12u1	DSA-5558-1
netty	source	(unstable)	1:4.1.48-8		1038947

Notes

[buster] - netty <not-affected> (SslClientHelloHandler introduced in v4.1.46)
https://github.com/netty/netty/security/advisories/GHSA-6mjq-h674-j845
https://github.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32 (netty-4.1.94.Final)