Amazon Linux 2023: CVE-2024-3652: Medium priority package update for libreswan

The Libreswan Project was notified of an issue causing libreswan to restart when using IKEv1 without specifying an esp= line. When the peer requests AES-GMAC, libreswan's default proposal handler causes an assertion failure and crashes and restarts. IKEv2 connections are not affected.
A flaw was found in Libreswan, where it was identified to contain an assertion failure issue in the compute_proto_keymat() function. The vulnerability can be exploited when an IKEv1 connection is loaded with an AH/ESP default setting when no esp= line is present in the connection. This flaw allows an authenticated attacker to send the bogus AES-GMAC proposal request, triggering the issue and causing Libreswan to crash and restart. When this connection is automatically added on startup using the auto= keyword, it can cause repeated crashes, leading to a denial of service. No remote code execution is possible.