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.

How to fix CVE-2023-34462

To remediate CVE-2023-34462, upgrade the affected package to a fixed version below.

• —upgrade to 1:4.1.48-4+deb11u2 or later
• —upgrade to 1:4.1.48-4+deb11u2 or later
• —upgrade to 4.1.94.Final or later

Is CVE-2023-34462 being exploited?

Low — EPSS is 0.7%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• from 0, < 1:4.1.48-4+deb11u2
• from 0, < 1:4.1.48-4+deb11u2
• from 0, < 4.1.94.Final

CVSS scores

References (8)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2023-34462
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2023-34462
• PATCHgithub.com/netty/netty
• WEBgithub.com/netty/netty/commit/535da17e45201ae4278c0479e6162bb4127d4c32