The nfs-utils packages provide a daemon for the kernel Network File System server, and related tools such as the mount.nfs, umount.nfs, and showmount programs. A flaw was found in the way nfs-utils performed IP based authentication of mount requests. In configurations where a directory was exported to a group of systems using a DNS wildcard or NIS netgroup, an attacker could possibly gain access to other directories exported to a specific host or subnet, bypassing intended access restrictions. It was found that the mount.nfs tool did not handle certain errors correctly when updating the mtab file. A local attacker could use this flaw to corrupt the mtab file. This update also fixes several bugs and adds an enhancement. Documentation for these bug fixes and the enhancement will be available shortly from the Technical Notes document, linked to in the References section. Users of nfs-utils are advised to upgrade to these updated packages, which contain backported patches to resolve these issues and add this enhancement. After installing this update, the nfs service will be restarted automatically.