Quagga is an open source implementation of TCP/IP routing software. Herbert Xu reported that Quagga can accept spoofed messages sent on the kernel netlink interface by other users on the local machine. This could lead to a local denial of service attack. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CAN-2003-0858 to this issue. Users of Quagga should upgrade to these erratum packages, which contain a patch that checks that netlink messages actually came from the kernel. This erratum also includes quagga-devel and quagga-contrib packages which were not originally shipped with Red Hat Enterprise Linux 3.