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Ubuntu 10.04 LTS USN-1008-2 Moderate: Libvirt Disk Format Threat

Libvirt in Ubuntu 10.04 LTS now no longer probes qemu disks for the image format and defaults to 'raw' when the format is not specified in the XML. This change in behavior breaks virt-install --import because virtinst in Ubuntu 10.04 LTS did not allow for specifying a disk format and does not specify a format in the XML. This update adds the 'format=' option when [More...]. ==========================================================Ubuntu Security Notice USN-1008-2 October 21, 2010 virtinst update https://bugs.launchpad.net/ubuntu/+source/virtinst/+bug/655392 ========================================================== A security issue affects the following Ubuntu releases: Ubuntu 10.04 LTS This advisory also applies to the corresponding versions of Kubuntu, Edubuntu, and Xubuntu. The problem can be corrected by upgrading your system to the following package versions: Ubuntu 10.04 LTS: virtinst 0.500.1-2ubuntu6.1 In general, a standard system update will make all the necessary changes. Details follow: Libvirt in Ubuntu 10.04 LTS now no longer probes qemu disks for the image format and defaults to 'raw' when the format is not specified in the XML. This change in behavior breaks virt-install --import because virtinst in Ubuntu 10.04 LTS did not allow for specifying a disk format and does not specify a format in the XML. This update adds the 'format=' option when specifying a disk. For example, to import an existing VM which uses a qcow2 disk format, use somthing like the following: virt-install --connect=qemu:///session --name test-import --ram=256 \ --disk path= ,format=qcow2 --import For more information, see man 1 virt-install. Original advisory details: It was discovered that libvirt would probe disk backing stores without consulting the defined format for the disk. A privileged attacker in the guest could exploit this to read arbitrary files on the host. This issue only affected Ubuntu 10.04 LTS. By default, guestsare confined by an AppArmor profile which provided partial protection against this flaw. (CVE-2010-2237, CVE-2010-2238) It was discovered that libvirt would create new VMs without setting a backing store format. A privileged attacker in the guest could exploit this to read arbitrary files on the host. This issue did not affect Ubuntu 8.04 LTS. In Ubuntu 9.10 and later guests are confined by an AppArmor profile which provided partial protection against this flaw. (CVE-2010-2239) Jeremy Nickurak discovered that libvirt created iptables rules with too lenient mappings of source ports. A privileged attacker in the guest could bypass intended restrictions to access privileged resources on the host. (CVE-2010-2242) Updated packages for Ubuntu 10.04 LTS: Source archives: Size/MD5: 11109 9e7424ceeab64e557fb589496aac69e9 Size/MD5: 2155 58fffa8f010cd5d3c8b3a709da9e1311 Size/MD5: 428911 f87ccfe2b77823c9e06d32e8b6f20424 Architecture independent packages: Size/MD5: 1564 402d23ff10bc82ffaec3554c883399ea Size/MD5: 230728 a958ec144ad1a7bdb3e4e1c25173fcdf . Ubuntu 10.04 LTS has its Libvirt configuration set to 'raw' by default, which poses a significant security risk and necessitates an immediate patch.. virtinst Update, Ubuntu Security Notice, Libvirt Threat, Image Format Attack. . Severity: Important. LinuxSecurity.com Team

Oct 22, 2010 •Important Ubuntu