The x86 emulator in KVM 83, when a guest is configured for Symmetric Multiprocessing (SMP), does not use the Current Privilege Level (CPL) and I/O Privilege Level (IOPL) to restrict instruction execution, which allows guest OS users to cause a denial of service (guest OS crash) or gain privileges on the guest OS by leveraging access to a (1) IO port or (2) MMIO region, and replacing an instruction in between emulator entry and instruction fetch, a related issue to CVE-2010-0298.

From Red Hat Security Advisory 2010:0088 :

Updated kvm packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 5.

This update has been rated as having important security impact by the Red Hat Security Response Team.

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for the standard Red Hat Enterprise Linux kernel.

The x86 emulator implementation was missing a check for the Current Privilege Level (CPL) and I/O Privilege Level (IOPL). A user in a guest could leverage these flaws to cause a denial of service (guest crash) or possibly escalate their privileges within that guest.
(CVE-2010-0298, CVE-2010-0306)

A flaw was found in the Programmable Interval Timer (PIT) emulation.
Access to the internal data structure pit_state, which represents the data state of the emulated PIT, was not properly validated in the pit_ioport_read() function. A privileged guest user could use this flaw to crash the host. (CVE-2010-0309)

A flaw was found in the USB passthrough handling code. A specially crafted USB packet sent from inside a guest could be used to trigger a buffer overflow in the usb_host_handle_control() function, which runs under the QEMU-KVM context on the host. A user in a guest could leverage this flaw to cause a denial of service (guest hang or crash) or possibly escalate their privileges within the host. (CVE-2010-0297)

This update also fixes the following bugs :

* pvclock MSR values were not preserved during remote migration, causing time drift for guests. (BZ#537028)

* SMBIOS table 4 data is now generated for Windows guests. (BZ#545874)

* if the qemu-kvm '-net user' option was used, unattended Windows XP installations did not receive an IP address after reboot. (BZ#546562)

* when being restored from migration, a race condition caused Windows Server 2008 R2 guests to hang during shutdown. (BZ#546563)

* the kernel symbol checking on the kvm-kmod build process has a safety check for ABI changes. (BZ#547293)

* on hosts without high-res timers, Windows Server 2003 guests experienced significant time drift. (BZ#547625)

* in some situations, installing Windows Server 2008 R2 from an ISO image resulted in a blue screen 'BAD_POOL_HEADER' stop error.
(BZ#548368)

* a bug in the grow_refcount_table() error handling caused infinite recursion in some cases. This caused the qemu-kvm process to hang and eventually crash. (BZ#552159)

* for Windows Server 2003 R2, Service Pack 2, 32-bit guests, an 'unhandled vm exit' error could occur during reboot on some systems.
(BZ#552518)

* for Windows guests, QEMU could attempt to stop a stopped audio device, resulting in a 'snd_playback_stop: ASSERT playback_channel->base.active failed' error. (BZ#552519)

* the Hypercall driver did not reset the device on power-down.
(BZ#552528)

* mechanisms have been added to make older savevm versions to be emitted in some cases. (BZ#552529)

* an error in the Makefile prevented users from using the source RPM to install KVM. (BZ#552530)

* guests became unresponsive and could use up to 100% CPU when running certain benchmark tests with more than 7 guests running simultaneously. (BZ#553249)

* QEMU could terminate randomly with virtio-net and SMP enabled.
(BZ#561022)

All KVM users should upgrade to these updated packages, which contain backported patches to resolve these issues. Note: The procedure in the Solution section must be performed before this update will take effect.

The remote Redhat Enterprise Linux 5 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2010:0088 advisory.

  - kvm-userspace-rhel5: usb-linux.c: fix buffer overflow (CVE-2010-0297)

  - kvm: emulator privilege escalation (CVE-2010-0298)

  - kvm: emulator privilege escalation IOPL/CPL level check (CVE-2010-0306)

  - kvm: cat /dev/port in guest cause the host hang (CVE-2010-0309)

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

The x86 emulator implementation was missing a check for the Current Privilege Level (CPL) and I/O Privilege Level (IOPL). A user in a guest could leverage these flaws to cause a denial of service (guest crash) or possibly escalate their privileges within that guest.
(CVE-2010-0298, CVE-2010-0306)

A flaw was found in the Programmable Interval Timer (PIT) emulation.
Access to the internal data structure pit_state, which represents the data state of the emulated PIT, was not properly validated in the pit_ioport_read() function. A privileged guest user could use this flaw to crash the host. (CVE-2010-0309)

A flaw was found in the USB passthrough handling code. A specially crafted USB packet sent from inside a guest could be used to trigger a buffer overflow in the usb_host_handle_control() function, which runs under the QEMU-KVM context on the host. A user in a guest could leverage this flaw to cause a denial of service (guest hang or crash) or possibly escalate their privileges within the host. (CVE-2010-0297)

This update also fixes the following bugs :

  - pvclock MSR values were not preserved during remote     migration, causing time drift for guests. (BZ#537028)

  - SMBIOS table 4 data is now generated for Windows guests.
    (BZ#545874)

  - if the qemu-kvm '-net user' option was used, unattended     Windows XP installations did not receive an IP address     after reboot. (BZ#546562)

  - when being restored from migration, a race condition     caused Windows Server 2008 R2 guests to hang during     shutdown. (BZ#546563)

  - the kernel symbol checking on the kvm-kmod build process     has a safety check for ABI changes. (BZ#547293)

  - on hosts without high-res timers, Windows Server 2003     guests experienced significant time drift. (BZ#547625)

  - in some situations, installing Windows Server 2008 R2     from an ISO image resulted in a blue screen     'BAD_POOL_HEADER' stop error. (BZ#548368)

  - a bug in the grow_refcount_table() error handling caused     infinite recursion in some cases. This caused the     qemu-kvm process to hang and eventually crash.
    (BZ#552159)

  - for Windows Server 2003 R2, Service Pack 2, 32-bit     guests, an 'unhandled vm exit' error could occur during     reboot on some systems. (BZ#552518)

  - for Windows guests, QEMU could attempt to stop a stopped     audio device, resulting in a 'snd_playback_stop: ASSERT     playback_channel->base.active failed' error. (BZ#552519)

  - the Hypercall driver did not reset the device on     power-down. (BZ#552528)

  - mechanisms have been added to make older savevm versions     to be emitted in some cases. (BZ#552529)

  - an error in the Makefile prevented users from using the     source RPM to install KVM. (BZ#552530)

  - guests became unresponsive and could use up to 100% CPU     when running certain benchmark tests with more than 7     guests running simultaneously. (BZ#553249)

  - QEMU could terminate randomly with virtio-net and SMP     enabled. (BZ#561022)

NOTE - The following procedure must be performed before this update will take effect :

1) Stop all KVM guest virtual machines.

2) Either reboot the hypervisor machine or, as the root user, remove (using 'modprobe -r [module]') and reload (using 'modprobe [module]') all of the following modules which are currently running (determined using 'lsmod'): kvm, ksm, kvm-intel or kvm-amd.

3) Restart the KVM guest virtual machines.

USN-947-1 fixed vulnerabilities in the Linux kernel. Fixes for CVE-2010-0419 caused failures when using KVM in certain situations.
This update reverts that fix until a better solution can be found.

We apologize for the inconvenience.

It was discovered that the Linux kernel did not correctly handle memory protection of the Virtual Dynamic Shared Object page when running a 32-bit application on a 64-bit kernel. A local attacker could exploit this to cause a denial of service. (Only affected Ubuntu 6.06 LTS.) (CVE-2009-4271)

It was discovered that the r8169 network driver did not correctly check the size of Ethernet frames. A remote attacker could send specially crafted traffic to crash the system, leading to a denial of service. (CVE-2009-4537)

Wei Yongjun discovered that SCTP did not correctly validate certain chunks. A remote attacker could send specially crafted traffic to monopolize CPU resources, leading to a denial of service. (Only affected Ubuntu 6.06 LTS.) (CVE-2010-0008)

It was discovered that KVM did not correctly limit certain privileged IO accesses on x86. Processes in the guest OS with access to IO regions could gain further privileges within the guest OS. (Did not affect Ubuntu 6.06 LTS.) (CVE-2010-0298, CVE-2010-0306, CVE-2010-0419)

Evgeniy Polyakov discovered that IPv6 did not correctly handle certain TUN packets. A remote attacker could exploit this to crash the system, leading to a denial of service.
(Only affected Ubuntu 8.04 LTS.) (CVE-2010-0437)

Sachin Prabhu discovered that GFS2 did not correctly handle certain locks. A local attacker with write access to a GFS2 filesystem could exploit this to crash the system, leading to a denial of service. (CVE-2010-0727)

Jamie Strandboge discovered that network virtio in KVM did not correctly handle certain high-traffic conditions. A remote attacker could exploit this by sending specially crafted traffic to a guest OS, causing the guest to crash, leading to a denial of service. (Only affected Ubuntu 8.04 LTS.) (CVE-2010-0741)

Marcus Meissner discovered that the USB subsystem did not correctly handle certain error conditions. A local attacker with access to a USB device could exploit this to read recently used kernel memory, leading to a loss of privacy and potentially root privilege escalation. (CVE-2010-1083)

Neil Brown discovered that the Bluetooth subsystem did not correctly handle large amounts of traffic. A physically proximate remote attacker could exploit this by sending specially crafted traffic that would consume all available system memory, leading to a denial of service. (Ubuntu 6.06 LTS and 10.04 LTS were not affected.) (CVE-2010-1084)

Jody Bruchon discovered that the sound driver for the AMD780V did not correctly handle certain conditions. A local attacker with access to this hardward could exploit the flaw to cause a system crash, leading to a denial of service.
(CVE-2010-1085)

Ang Way Chuang discovered that the DVB driver did not correctly handle certain MPEG2-TS frames. An attacker could exploit this by delivering specially crafted frames to monopolize CPU resources, leading to a denial of service.
(Ubuntu 10.04 LTS was not affected.) (CVE-2010-1086)

Trond Myklebust discovered that NFS did not correctly handle truncation under certain conditions. A local attacker with write access to an NFS share could exploit this to crash the system, leading to a denial of service. (Ubuntu 10.04 LTS was not affected.) (CVE-2010-1087)

Al Viro discovered that automount of NFS did not correctly handle symlinks under certain conditions. A local attacker could exploit this to crash the system, leading to a denial of service. (Ubuntu 6.06 LTS and Ubuntu 10.04 LTS were not affected.) (CVE-2010-1088)

Matt McCutchen discovered that ReiserFS did not correctly protect xattr files in the .reiserfs_priv directory. A local attacker could exploit this to gain root privileges or crash the system, leading to a denial of service. (CVE-2010-1146)

Eugene Teo discovered that CIFS did not correctly validate arguments when creating new files. A local attacker could exploit this to crash the system, leading to a denial of service, or possibly gain root privileges if mmap_min_addr was not set. (CVE-2010-1148)

Catalin Marinas and Tetsuo Handa discovered that the TTY layer did not correctly release process IDs. A local attacker could exploit this to consume kernel resources, leading to a denial of service. (CVE-2010-1162)

Neil Horman discovered that TIPC did not correctly check its internal state. A local attacker could send specially crafted packets via AF_TIPC that would cause the system to crash, leading to a denial of service. (Ubuntu 6.06 LTS was not affected.) (CVE-2010-1187)

Masayuki Nakagawa discovered that IPv6 did not correctly handle certain settings when listening. If a socket were listening with the IPV6_RECVPKTINFO flag, a remote attacker could send specially crafted traffic that would cause the system to crash, leading to a denial of service. (Only Ubuntu 6.06 LTS was affected.) (CVE-2010-1188)

Oleg Nesterov discovered that the Out-Of-Memory handler did not correctly handle certain arrangements of processes. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2010-1488).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

It was discovered that the Linux kernel did not correctly handle memory protection of the Virtual Dynamic Shared Object page when running a 32-bit application on a 64-bit kernel. A local attacker could exploit this to cause a denial of service. (Only affected Ubuntu 6.06 LTS.) (CVE-2009-4271)

It was discovered that the r8169 network driver did not correctly check the size of Ethernet frames. A remote attacker could send specially crafted traffic to crash the system, leading to a denial of service. (CVE-2009-4537)

Wei Yongjun discovered that SCTP did not correctly validate certain chunks. A remote attacker could send specially crafted traffic to monopolize CPU resources, leading to a denial of service. (Only affected Ubuntu 6.06 LTS.) (CVE-2010-0008)

It was discovered that KVM did not correctly limit certain privileged IO accesses on x86. Processes in the guest OS with access to IO regions could gain further privileges within the guest OS. (Did not affect Ubuntu 6.06 LTS.) (CVE-2010-0298, CVE-2010-0306, CVE-2010-0419)

Evgeniy Polyakov discovered that IPv6 did not correctly handle certain TUN packets. A remote attacker could exploit this to crash the system, leading to a denial of service. (Only affected Ubuntu 8.04 LTS.) (CVE-2010-0437)

Sachin Prabhu discovered that GFS2 did not correctly handle certain locks. A local attacker with write access to a GFS2 filesystem could exploit this to crash the system, leading to a denial of service.
(CVE-2010-0727)

Jamie Strandboge discovered that network virtio in KVM did not correctly handle certain high-traffic conditions. A remote attacker could exploit this by sending specially crafted traffic to a guest OS, causing the guest to crash, leading to a denial of service. (Only affected Ubuntu 8.04 LTS.) (CVE-2010-0741)

Marcus Meissner discovered that the USB subsystem did not correctly handle certain error conditions. A local attacker with access to a USB device could exploit this to read recently used kernel memory, leading to a loss of privacy and potentially root privilege escalation.
(CVE-2010-1083)

Neil Brown discovered that the Bluetooth subsystem did not correctly handle large amounts of traffic. A physically proximate remote attacker could exploit this by sending specially crafted traffic that would consume all available system memory, leading to a denial of service. (Ubuntu 6.06 LTS and 10.04 LTS were not affected.) (CVE-2010-1084)

Jody Bruchon discovered that the sound driver for the AMD780V did not correctly handle certain conditions. A local attacker with access to this hardward could exploit the flaw to cause a system crash, leading to a denial of service. (CVE-2010-1085)

Ang Way Chuang discovered that the DVB driver did not correctly handle certain MPEG2-TS frames. An attacker could exploit this by delivering specially crafted frames to monopolize CPU resources, leading to a denial of service. (Ubuntu 10.04 LTS was not affected.) (CVE-2010-1086)

Trond Myklebust discovered that NFS did not correctly handle truncation under certain conditions. A local attacker with write access to an NFS share could exploit this to crash the system, leading to a denial of service. (Ubuntu 10.04 LTS was not affected.) (CVE-2010-1087)

Al Viro discovered that automount of NFS did not correctly handle symlinks under certain conditions. A local attacker could exploit this to crash the system, leading to a denial of service. (Ubuntu 6.06 LTS and Ubuntu 10.04 LTS were not affected.) (CVE-2010-1088)

Matt McCutchen discovered that ReiserFS did not correctly protect xattr files in the .reiserfs_priv directory. A local attacker could exploit this to gain root privileges or crash the system, leading to a denial of service. (CVE-2010-1146)

Eugene Teo discovered that CIFS did not correctly validate arguments when creating new files. A local attacker could exploit this to crash the system, leading to a denial of service, or possibly gain root privileges if mmap_min_addr was not set. (CVE-2010-1148)

Catalin Marinas and Tetsuo Handa discovered that the TTY layer did not correctly release process IDs. A local attacker could exploit this to consume kernel resources, leading to a denial of service.
(CVE-2010-1162)

Neil Horman discovered that TIPC did not correctly check its internal state. A local attacker could send specially crafted packets via AF_TIPC that would cause the system to crash, leading to a denial of service. (Ubuntu 6.06 LTS was not affected.) (CVE-2010-1187)

Masayuki Nakagawa discovered that IPv6 did not correctly handle certain settings when listening. If a socket were listening with the IPV6_RECVPKTINFO flag, a remote attacker could send specially crafted traffic that would cause the system to crash, leading to a denial of service. (Only Ubuntu 6.06 LTS was affected.) (CVE-2010-1188)

Oleg Nesterov discovered that the Out-Of-Memory handler did not correctly handle certain arrangements of processes. A local attacker could exploit this to crash the system, leading to a denial of service. (CVE-2010-1488).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Several local vulnerabilities have been discovered in kvm, a full virtualization system. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2010-0298 CVE-2010-0306     Gleb Natapov discovered issues in the KVM subsystem     where missing permission checks (CPL/IOPL) permit a user     in a guest system to denial of service a guest (system     crash) or gain escalated privileges with the guest.

  - CVE-2010-0309     Marcelo Tosatti fixed an issue in the PIT emulation code     in the KVM subsystem that allows privileged users in a     guest domain to cause a denial of service (crash) of the     host system.

  - CVE-2010-0419     Paolo Bonzini found a bug in KVM that can be used to     bypass proper permission checking while loading segment     selectors. This potentially allows privileged guest     users to execute privileged instructions on the host     system.

Several vulnerabilities have been discovered in the Linux kernel that may lead to a denial of service, sensitive memory leak or privilege escalation. The Common Vulnerabilities and Exposures project identifies the following problems :

  - CVE-2009-3939     Joseph Malicki reported that the dbg_lvl sysfs attribute     for the megaraid_sas device driver had world-writable     permissions, permitting local users to modify logging     settings.

  - CVE-2009-4027     Lennert Buytenhek reported a race in the mac80211     subsystem that may allow remote users to cause a denial     of service (system crash) on a system connected to the     same wireless network.

  - CVE-2009-4536 CVE-2009-4538     Fabian Yamaguchi reported issues in the e1000 and e1000e     drivers for Intel gigabit network adapters which allow     remote users to bypass packet filters using specially     crafted ethernet frames.

  - CVE-2010-0003     Andi Kleen reported a defect which allows local users to     gain read access to memory reachable by the kernel when     the print-fatal-signals option is enabled. This option     is disabled by default.

  - CVE-2010-0007     Florian Westphal reported a lack of capability checking     in the ebtables netfilter subsystem. If the ebtables     module is loaded, local users can add and modify     ebtables rules.

  - CVE-2010-0291     Al Viro reported several issues with the mmap/mremap     system calls that allow local users to cause a denial of     service (system panic) or obtain elevated privileges.

  - CVE-2010-0298 & CVE-2010-0306     Gleb Natapov discovered issues in the KVM subsystem     where missing permission checks (CPL/IOPL) permit a user     in a guest system to denial of service a guest (system     crash) or gain escalated privileges with the guest.

  - CVE-2010-0307     Mathias Krause reported an issue with the     load_elf_binary code on the amd64 flavor kernels that     allows local users to cause a denial of service (system     crash).

  - CVE-2010-0309     Marcelo Tosatti fixed an issue in the PIT emulation code     in the KVM subsystem that allows privileged users in a     guest domain to cause a denial of service (crash) of the     host system.

  - CVE-2010-0410     Sebastian Krahmer discovered an issue in the netlink     connector subsystem that permits local users to allocate     large amounts of system memory resulting in a denial of     service (out of memory).

  - CVE-2010-0415     Ramon de Carvalho Valle discovered an issue in the     sys_move_pages interface, limited to amd64, ia64 and     powerpc64 flavors in Debian. Local users can exploit     this issue to cause a denial of service (system crash)     or gain access to sensitive kernel memory.

Updated kvm packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 5.

This update has been rated as having important security impact by the Red Hat Security Response Team.

KVM (Kernel-based Virtual Machine) is a full virtualization solution for Linux on AMD64 and Intel 64 systems. KVM is a Linux kernel module built for the standard Red Hat Enterprise Linux kernel.

The x86 emulator implementation was missing a check for the Current Privilege Level (CPL) and I/O Privilege Level (IOPL). A user in a guest could leverage these flaws to cause a denial of service (guest crash) or possibly escalate their privileges within that guest.
(CVE-2010-0298, CVE-2010-0306)

A flaw was found in the Programmable Interval Timer (PIT) emulation.
Access to the internal data structure pit_state, which represents the data state of the emulated PIT, was not properly validated in the pit_ioport_read() function. A privileged guest user could use this flaw to crash the host. (CVE-2010-0309)

A flaw was found in the USB passthrough handling code. A specially crafted USB packet sent from inside a guest could be used to trigger a buffer overflow in the usb_host_handle_control() function, which runs under the QEMU-KVM context on the host. A user in a guest could leverage this flaw to cause a denial of service (guest hang or crash) or possibly escalate their privileges within the host. (CVE-2010-0297)

This update also fixes the following bugs :

* pvclock MSR values were not preserved during remote migration, causing time drift for guests. (BZ#537028)

* SMBIOS table 4 data is now generated for Windows guests. (BZ#545874)

* if the qemu-kvm '-net user' option was used, unattended Windows XP installations did not receive an IP address after reboot. (BZ#546562)

* when being restored from migration, a race condition caused Windows Server 2008 R2 guests to hang during shutdown. (BZ#546563)

* the kernel symbol checking on the kvm-kmod build process has a safety check for ABI changes. (BZ#547293)

* on hosts without high-res timers, Windows Server 2003 guests experienced significant time drift. (BZ#547625)

* in some situations, installing Windows Server 2008 R2 from an ISO image resulted in a blue screen 'BAD_POOL_HEADER' stop error.
(BZ#548368)

* a bug in the grow_refcount_table() error handling caused infinite recursion in some cases. This caused the qemu-kvm process to hang and eventually crash. (BZ#552159)

* for Windows Server 2003 R2, Service Pack 2, 32-bit guests, an 'unhandled vm exit' error could occur during reboot on some systems.
(BZ#552518)

* for Windows guests, QEMU could attempt to stop a stopped audio device, resulting in a 'snd_playback_stop: ASSERT playback_channel->base.active failed' error. (BZ#552519)

* the Hypercall driver did not reset the device on power-down.
(BZ#552528)

* mechanisms have been added to make older savevm versions to be emitted in some cases. (BZ#552529)

* an error in the Makefile prevented users from using the source RPM to install KVM. (BZ#552530)

* guests became unresponsive and could use up to 100% CPU when running certain benchmark tests with more than 7 guests running simultaneously. (BZ#553249)

* QEMU could terminate randomly with virtio-net and SMP enabled.
(BZ#561022)

All KVM users should upgrade to these updated packages, which contain backported patches to resolve these issues. Note: The procedure in the Solution section must be performed before this update will take effect.

ID	Name	Product	Family	Severity
67993	Oracle Linux 5 : kvm (ELSA-2010-0088)	Nessus	Oracle Linux Local Security Checks	high
63916	RHEL 5 : kvm (RHSA-2010:0088)	Nessus	Red Hat Local Security Checks	high
60730	Scientific Linux Security Update : kvm on SL5.4 i386/x86_64	Nessus	Scientific Linux Local Security Checks	high
46811	Ubuntu 10.04 LTS : linux regression (USN-947-2)	Nessus	Ubuntu Local Security Checks	high
46810	Ubuntu 6.06 LTS / 8.04 LTS / 9.04 / 9.10 / 10.04 LTS : linux, linux-source-2.6.15 vulnerabilities (USN-947-1)	Nessus	Ubuntu Local Security Checks	high
45026	Debian DSA-2010-1 : kvm - privilege escalation/denial of service	Nessus	Debian Local Security Checks	medium
44860	Debian DSA-1996-1 : linux-2.6 - privilege escalation/denial of service/sensitive memory leak	Nessus	Debian Local Security Checks	critical
44427	CentOS 5 : kvm (CESA-2010:0088)	Nessus	CentOS Local Security Checks	high

Detections

Analytics

CVE-2010-0306

high

Tenable Plugins

high

high

high

high

high

medium

critical

high