The issue affects the Quagga package in various Linux operating systems, including Red Hat Enterprise Linux, CentOS, SUSE Linux Enterprise, and openSUSE. It allows remote attackers to cause a denial of service (daemon crash) via an invalid Link State Advertisement (LSA) type in an IPv4 Link State Update message. The `ospf flood` function in `ospf flood.c` in `ospfd` is vulnerable. This can lead to disruption of confidentiality, integrity, and availability of protected information.