The qemu guest agent in Qemu 1.4.1 and earlier, as used by Xen, when started in daemon mode, uses weak permissions for certain files, which allows local users to read and write to these files.

Updated qemu-kvm-rhev packages that fix one security issue and two bugs are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. The qemu-kvm-rhev packages form the user-space component for running virtual machines using KVM.

It was found that QEMU Guest Agent (the 'qemu-ga' service) created certain files with world-writable permissions when run in daemon mode (the default mode). An unprivileged guest user could use this flaw to consume all free space on the partition containing the qemu-ga log file, or modify the contents of the log. When a UNIX domain socket transport was explicitly configured to be used (not the default), an unprivileged guest user could potentially use this flaw to escalate their privileges in the guest. This update requires manual action.
Refer below for details. (CVE-2013-2007)

This update does not change the permissions of the existing log file or the UNIX domain socket. For these to be changed, stop the qemu-ga service, and then manually remove all 'group' and 'other' permissions on the affected files, or remove the files.

Note that after installing this update, files created by the guest-file-open QEMU Monitor Protocol (QMP) command will still continue to be created with world-writable permissions for backwards compatibility.

This issue was discovered by Laszlo Ersek of Red Hat.

This update also fixes the following bugs :

* Previously, due to integer overflow in code calculations, the qemu-kvm utility was reporting incorrect memory size on QMP events when using the virtio balloon driver with more than 4 GB of memory.
This update fixes the overflow in the code and qemu-kvm works as expected in the described scenario. (BZ#958750)

* When the set_link flag is set to 'off' to change the status of a network card, the status is changed to 'down' on the respective guest.
Previously, with certain network cards, when such a guest was restarted, the status of the network card was unexpectedly reset to 'up', even though the network was unavailable. A patch has been provided to address this bug and the link status change is now preserved across restarts for all network cards. (BZ#927591)

All users of qemu-kvm-rhev are advised to upgrade to these updated packages, which contain backported patches to correct these issues.
After installing this update, shut down all running virtual machines.
Once all virtual machines have shut down, start them again for this update to take effect.

XEN was updated to 4.2.2, fixing lots of bugs and several security issues.

Various upstream patches were also merged into this version by our developers.

Detailed buglist :

  - bnc#824676 - Failed to setup devices for vm instance     when start multiple vms simultaneously

  - bnc#817799 - sles9sp4 guest fails to start after     upgrading to sles11 sp3

  - bnc#826882 - xen: CVE-2013-1432: XSA-58: Page reference     counting error due to XSA-45/CVE-2013-1918 fixes

  - Add upstream patch to fix devid assignment in libxl     27184-libxl-devid-fix.patch

  - bnc#823608 - xen: XSA-57: libxl allows guest write     access to sensitive console related xenstore keys     27178-libxl-Restrict-permissions-on-PV-console-device-xe     nstore-nodes.patch

  - bnc#823011 - xen: XSA-55: Multiple vulnerabilities in     libelf PV kernel handling

  - bnc#808269 - Fully Virtualized Windows VM install is     failed on Ivy Bridge platforms with Xen kernel

  - bnc#801663 - performance of mirror lvm unsuitable for     production block-dmmd

  - bnc#817904 - [SLES11SP3 BCS Bug] Crashkernel fails to     boot after panic on XEN kernel SP3 Beta 4 and RC1

  - Upstream AMD Erratum patch from Jan

  - bnc#813675 - - xen: CVE-2013-1919: XSA-46: Several     access permission issues with IRQs for unprivileged     guests

  - bnc#820917 - CVE-2013-2076: xen: Information leak on     XSAVE/XRSTOR capable AMD CPUs (XSA-52)

  - bnc#820919 - CVE-2013-2077: xen: Hypervisor crash due to     missing exception recovery on XRSTOR (XSA-53)

  - bnc#820920 - CVE-2013-2078: xen: Hypervisor crash due to     missing exception recovery on XSETBV (XSA-54)

  - bnc#808085 - aacraid driver panics mapping INT A when     booting kernel-xen

  - bnc#817210 - openSUSE 12.3 Domain 0 doesn't boot with     i915 graphics controller under Xen with VT-d enabled

  - bnc#819416 - xen: CVE-2013-2072: XSA-56: Buffer overflow     in xencontrol Python bindings affecting xend

  - bnc#818183 - xen: CVE-2013-2007: XSA-51: qga set umask     0077 when daemonizing

  - add lndir to BuildRequires

  - remove     xen.migrate.tools_notify_restore_to_hangup_during_migrat     ion_--abort_if_busy.patch It changed migration protocol     and upstream wants a different solution

  - bnc#802221 - fix xenpaging readd     xenpaging.qemu.flush-cache.patch

  - bnc#808269 - Fully Virtualized Windows VM install is     failed on Ivy Bridge platforms with Xen kernel

  - Additional fix for bnc#816159     CVE-2013-1918-xsa45-followup.patch

  - bnc#817068 - Xen guest with >1 sr-iov vf won't start

  - Update to Xen 4.2.2 c/s 26064 The following recent     security patches are included in the tarball     CVE-2013-0151-xsa34.patch (bnc#797285)     CVE-2012-6075-xsa41.patch (bnc#797523)     CVE-2013-1917-xsa44.patch (bnc#813673)     CVE-2013-1919-xsa46.patch (bnc#813675)

  - bnc#816159 - xen: CVE-2013-1918: XSA-45: Several long     latency operations are not preemptible

  - bnc#816163 - xen: CVE-2013-1952: XSA-49: VT-d interrupt     remapping source validation flaw for bridges

  - bnc#809662 - can't use pv-grub to start domU (pygrub     does work) xen.spec

  - bnc#814709 - Unable to create XEN virtual machines in     SLED 11 SP2 on Kyoto

  - bnc#813673 - CVE-2013-1917: xen: Xen PV DoS     vulnerability with SYSENTER

  - bnc#813675 - CVE-2013-1919: xen: Several access     permission issues with IRQs for unprivileged guests

  - bnc#814059 - xen: qemu-nbd format-guessing due to     missing format specification

The qemu guest agent creates a bunch of files with insecure permissions when started in daemon mode. For now mask all file mode bits for 'group' and 'others' in become_daemon(). Temporarily, for compatibility reasons, stick with the 0666 file-mode in case of files newly created by the 'guest-file-open' QMP call. Do so without changing the umask temporarily.

QEMU was updated to 1.1.2 on openSUSE 12.2, and 1.3.1 on openSUSE 12.3.

The Xen hypervisor and tool-suite have been updated to fix security issues and bugs :

  - XSA-73: A lock order reversal between page allocation     and grant table locks could lead to host crashes or even     host code execution. (CVE-2013-4494)

  - XSA-74: A lock order reversal between page_alloc_lock     and mm_rwlock could lead to deadlocks. (CVE-2013-4553)

  - XSA-76: Hypercalls exposed to privilege rings 1 and 2 of     HVM guests which might lead to Hypervisor escalation     under specific circumstances. (CVE-2013-4554)

  - XSA-78: Insufficient TLB flushing in VT-d (iommu) code     could lead to access of memory that was revoked.
    (CVE-2013-6375)

  - XSA-75: A host crash due to guest VMX instruction     execution was fixed. Non-security bugs have also been     fixed:. (CVE-2013-4551)

  - It is possible to start a VM twice on the same node.
    (bnc#840997)

  - In HP's UEFI x86_64 platform and SLES 11-SP3, dom0 will     could lock-up on multiple blades nPar. (bnc#842417)

  - Xen Hypervisor panics on 8-blades nPar with 46-bit     memory addressing. (bnc#848014)

  - Soft lock-up with PCI pass-through and many VCPUs.
    (bnc#846849)

  - Boot Failure with Xen kernel in UEFI mode with error 'No     memory for trampoline'. (bnc#833483)

  - Increase the maximum supported CPUs in the Hypervisor to     512.

This update fixes a file permission issue with qga (the QEMU Guest Agent) from the qemu/kvm package and includes several bug-fixes.

(bnc#818182) (CVE-2013-2007) (bnc#786813) (bnc#725008) (bnc#712137).
(bnc#824340)

The remote Oracle Linux 6 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2013-0896 advisory.

    - kvm-qga-set-umask-0077-when-daemonizing-CVE-2013-2007.patch [bz#957056]
    - Resolves: bz#957056       (CVE-2013-2007 qemu: guest agent creates files with insecure permissions in deamon mode [rhel-6.4.z])

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

- Don't install conflicting binfmt handler on arm (bz     #974804)

    - Fix building docs with f19 texinfo

    - CVE-2013-2007: Fix qemu-ga file creation permissions       (bz #956082, bz #969455)

    - Fix rtl8139 + windows 7 + large transfers (bz #970240)

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.

Updated qemu-kvm packages that fix one security issue and two bugs are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component for running virtual machines using KVM.

It was found that QEMU Guest Agent (the 'qemu-ga' service) created certain files with world-writable permissions when run in daemon mode (the default mode). An unprivileged guest user could use this flaw to consume all free space on the partition containing the qemu-ga log file, or modify the contents of the log. When a UNIX domain socket transport was explicitly configured to be used (not the default), an unprivileged guest user could potentially use this flaw to escalate their privileges in the guest. This update requires manual action.
Refer below for details. (CVE-2013-2007)

This update does not change the permissions of the existing log file or the UNIX domain socket. For these to be changed, stop the qemu-ga service, and then manually remove all 'group' and 'other' permissions on the affected files, or remove the files.

Note that after installing this update, files created by the guest-file-open QEMU Monitor Protocol (QMP) command will still continue to be created with world-writable permissions for backwards compatibility.

This issue was discovered by Laszlo Ersek of Red Hat.

This update also fixes the following bugs :

* Previously, due to integer overflow in code calculations, the qemu-kvm utility was reporting incorrect memory size on QMP events when using the virtio balloon driver with more than 4 GB of memory.
This update fixes the overflow in the code and qemu-kvm works as expected in the described scenario. (BZ#958750)

* When the set_link flag is set to 'off' to change the status of a network card, the status is changed to 'down' on the respective guest.
Previously, with certain network cards, when such a guest was restarted, the status of the network card was unexpectedly reset to 'up', even though the network was unavailable. A patch has been provided to address this bug and the link status change is now preserved across restarts for all network cards. (BZ#927591)

All users of qemu-kvm should upgrade to these updated packages, which contain backported patches to correct these issues. After installing this update, shut down all running virtual machines. Once all virtual machines have shut down, start them again for this update to take effect.

It was found that QEMU Guest Agent (the 'qemu-ga' service) created certain files with world-writable permissions when run in daemon mode (the default mode). An unprivileged guest user could use this flaw to consume all free space on the partition containing the qemu-ga log file, or modify the contents of the log. When a UNIX domain socket transport was explicitly configured to be used (not the default), an unprivileged guest user could potentially use this flaw to escalate their privileges in the guest. This update requires manual action.
Refer below for details. (CVE-2013-2007)

This update does not change the permissions of the existing log file or the UNIX domain socket. For these to be changed, stop the qemu-ga service, and then manually remove all 'group' and 'other' permissions on the affected files, or remove the files.

Note that after installing this update, files created by the guest-file- open QEMU Monitor Protocol (QMP) command will still continue to be created with world-writable permissions for backwards compatibility.

This update also fixes the following bugs :

  - Previously, due to integer overflow in code     calculations, the qemu-kvm utility was reporting     incorrect memory size on QMP events when using the     virtio balloon driver with more than 4 GB of memory.
    This update fixes the overflow in the code and qemu-kvm     works as expected in the described scenario.

  - When the set_link flag is set to 'off' to change the     status of a network card, the status is changed to     'down' on the respective guest. Previously, with certain     network cards, when such a guest was restarted, the     status of the network card was unexpectedly reset to     'up', even though the network was unavailable. A patch     has been provided to address this bug and the link     status change is now preserved across restarts for all     network cards.

After installing this update, shut down all running virtual machines.
Once all virtual machines have shut down, start them again for this update to take effect.

ID	Name	Product	Family	Severity
78956	RHEL 6 : qemu-kvm-rhev (RHSA-2013:0791)	Nessus	Red Hat Local Security Checks	medium
75130	openSUSE Security Update : xen (openSUSE-SU-2013:1404-1)	Nessus	SuSE Local Security Checks	high
75088	openSUSE Security Update : qemu (openSUSE-SU-2013:1202-1)	Nessus	SuSE Local Security Checks	medium
71562	SuSE 11.3 Security Update : Xen (SAT Patch Number 8588)	Nessus	SuSE Local Security Checks	high
68979	SuSE 11.2 Security Update : KVM (SAT Patch Number 7906)	Nessus	SuSE Local Security Checks	medium
68831	Oracle Linux 6 : qemu-kvm (ELSA-2013-0896)	Nessus	Oracle Linux Local Security Checks	high
67309	Fedora 18 : qemu-1.2.2-13.fc18 (2013-11407)	Nessus	Fedora Local Security Checks	medium
66791	CentOS 6 : qemu-kvm (CESA-2013:0896)	Nessus	CentOS Local Security Checks	medium
66780	Scientific Linux Security Update : qemu-kvm on SL6.x i386/x86_64 (20130603)	Nessus	Scientific Linux Local Security Checks	medium
66771	RHEL 6 : qemu-kvm (RHSA-2013:0896)	Nessus	Red Hat Local Security Checks	medium

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