CVE-2023-34462

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.