Fedora 13 : libvirt-0.8.2-1.fc13 (2010-10960)
Medium Nessus Plugin ID 47838
SynopsisThe remote Fedora host is missing a security update.
DescriptionA reboot is required to update the iptables rules for the default virtual network to address the CVE-2010-2242 All disk format probing is now disabled in a default installation of libvirt. This change may prevent KVM guests using qcow2 disks from booting successfully. If this occurs verify that the guest XML <disk> element has explicitly requested use of the qcow2 data format via the <driver> element:
<driver name='qemu' type='qcow2'/> If the qcow2 is using an external backing file, it may be necessary to re-create the qcow2 file, explicitly specifying the backing store format with the '-o' option.
qemu- img create -f qcow2 -b master.qcow2 -o backing_fmt=qcow2 newdisk.qcow2 If this is not possible, disk format probing can be re-enabled via /etc/libvirt/qemu.conf allow_disk_format_probing = 1 NB, enabling disk format probing has security consequences as per the linked CVEs.
Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.
SolutionUpdate the affected libvirt package.