Executive Summary

Summary
Title kvm security and bug fix update
Informations
Name RHSA-2010:0998 First vendor Publication 2010-12-20
Vendor RedHat Last vendor Modification 2010-12-20
Severity (Vendor) Low Revision 01

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
 
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:M/Au:N/C:P/I:N/A:N)
Cvss Base Score 1.9 Attack Range Local
Cvss Impact Score 2.9 Attack Complexity Medium
Cvss Expoit Score 3.4 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

Problem Description:

Updated kvm packages that fix one security issue and three bugs are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low 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.

2. Relevant releases/architectures:

RHEL Desktop Multi OS (v. 5 client) - x86_64 RHEL Virtualization (v. 5 server) - x86_64

3. Description:

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.

It was found that some structure padding and reserved fields in certain data structures in QEMU-KVM were not initialized properly before being copied to user-space. A privileged host user with access to "/dev/kvm" could use this flaw to leak kernel stack memory to user-space. (CVE-2010-3881)

Red Hat would like to thank Vasiliy Kulikov for reporting this issue.

This update also fixes the following bugs:

* The 'kvm_amd' kernel module did not initialize the TSC (Time Stamp Counter) offset in the VMCB (Virtual Machine Control Block) correctly. After a vCPU (virtual CPU) has been created, the TSC offset in the VMCB should have a negative value so that the virtual machine will see TSC values starting at zero. However, the TSC offset was set to zero and therefore the virtual machine saw the same TSC value as the host. With this update, the TSC offset has been updated to show the correct values. (BZ#656984)

* Setting the boot settings of a virtual machine to, firstly, boot from PXE and, secondly, to boot from the hard drive would result in a PXE boot loop, that is, the virtual machine would not continue to boot from the hard drive if the PXE boot failed. This was caused by a flaw in the 'bochs-bios' (part of KVM) code. With this update, after a virtual machine tries to boot from PXE and fails, it continues to boot from a hard drive if there is one present. (BZ#659850)

* If a 64-bit Red Hat Enterprise Linux 5.5 virtual machine was migrated to another host with a different CPU clock speed, the clock of that virtual machine would consistently lose or gain time (approximately half a second for every second the host is running). On machines that do not use the kvm clock, the network time protocol daemon (ntpd) could correct the time drifts caused by migration. However, using the pvclock caused the time to change consistently. This was due to flaws in the save/load functions of pvclock. With this update, the issue has been fixed and migrating a virtual machine no longer causes time drift. (BZ#660239)

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

4. Solution:

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at http://kbase.redhat.com/faq/docs/DOC-11259

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.

5. Bugs fixed (http://bugzilla.redhat.com/):

649920 - CVE-2010-3881 kvm: arch/x86/kvm/x86.c: reading uninitialized stack memory 656984 - TSC offset of virtual machines is not initialized correctly by 'kvm_amd' kernel module. 659850 - If VM boot seq. is set up as nc (PXE then disk) the VM is always stuck on trying to PXE boot 660239 - clock drift when migrating a guest between mis-matched CPU clock speed

Original Source

Url : https://rhn.redhat.com/errata/RHSA-2010-0998.html

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-200 Information Exposure

OVAL Definitions

Definition Id: oval:org.mitre.oval:def:22207
 
Oval ID: oval:org.mitre.oval:def:22207
Title: RHSA-2010:0998: kvm security and bug fix update (Low)
Description: arch/x86/kvm/x86.c in the Linux kernel before 2.6.36.2 does not initialize certain structure members, which allows local users to obtain potentially sensitive information from kernel stack memory via read operations on the /dev/kvm device.
Family: unix Class: patch
Reference(s): RHSA-2010:0998-01
CVE-2010-3881
Version: 4
Platform(s): Red Hat Enterprise Linux 5
Product(s): kvm
Definition Synopsis:
Definition Id: oval:org.mitre.oval:def:23262
 
Oval ID: oval:org.mitre.oval:def:23262
Title: ELSA-2010:0998: kvm security and bug fix update (Low)
Description: arch/x86/kvm/x86.c in the Linux kernel before 2.6.36.2 does not initialize certain structure members, which allows local users to obtain potentially sensitive information from kernel stack memory via read operations on the /dev/kvm device.
Family: unix Class: patch
Reference(s): ELSA-2010:0998-01
CVE-2010-3881
Version: 6
Platform(s): Oracle Linux 5
Product(s): kvm
Definition Synopsis:
Definition Id: oval:org.mitre.oval:def:27628
 
Oval ID: oval:org.mitre.oval:def:27628
Title: DEPRECATED: ELSA-2010-0998 -- kvm security and bug fix update (low)
Description: [kvm-83-164.0.1.el5_5.30] - Added kvm-add-oracle-workaround-for-libvirt-bug.patch to replace RHEL with OEL - Added kvm-Introduce-oel-machine-type.patch so that OEL is a recognized VM [kvm-83-164.el5_5.30] - Revert the bz#661397 patches as they are not enough - kvm-kernel-Revert-KVM-VMX-Return-0-from-a-failed-VMREAD.patch [bz#661397] - kvm-kernel-Revert-KVM-Don-t-spin-on-virt-instruction-faults-dur.patch [bz#661397] - Related: bz#661397 (reboot(RB_AUTOBOOT) fails if kvm instance is running) - kvm-kernel-KVM-fix-AMD-initial-TSC-offset-problems-additional-f.patch [bz#656984] - Resolves: bz#656984 (TSC offset of virtual machines is not initialized correctly by 'kvm_amd' kernel module.) [kvm-83-164.el5_5.29] - kvm-kernel-KVM-Don-t-spin-on-virt-instruction-faults-during-reb.patch [bz#661397] - kvm-kernel-KVM-VMX-Return-0-from-a-failed-VMREAD.patch [bz#661397] - Resolves: bz#661397 (reboot(RB_AUTOBOOT) fails if kvm instance is running) [kvm-83-164.el5_5.28] - kvm-implement-dummy-PnP-support.patch [bz#659850] - kvm-load-registers-after-restoring-pvclock-msrs.patch [bz#660239] - Resolves: bz#659850 (If VM boot seq. is set up as nc (PXE then disk) the VM is always stuck on trying to PXE boot) - Resolves: bz#660239 (clock drift when migrating a guest between mis-matched CPU clock speed) [kvm-83-164.el5_5.27] - kvm-kernel-KVM-fix-AMD-initial-TSC-offset-problems.patch [bz#656984] - Resolves: bz#656984 (TSC offset of virtual machines is not initialized correctly by 'kvm_amd' kernel module.) [kvm-83-164.el5_5.26] - Updated kversion to 2.6.18-194.26.1.el5 to match build root - kvm-kernel-KVM-x86-fix-information-leak-to-userland.patch [bz#649832] - Resolves: bz#649832 (CVE-2010-3881 kvm: arch/x86/kvm/x86.c: reading uninitialized stack memory [5.5.z]) - CVE: CVE-2010-3881
Family: unix Class: patch
Reference(s): ELSA-2010-0998
CVE-2010-3881
Version: 4
Platform(s): Oracle Linux 5
Product(s): kvm
Definition Synopsis:

CPE : Common Platform Enumeration

TypeDescriptionCount
Application 1
Os 1347
Os 1
Os 1
Os 1
Os 1
Os 1

OpenVAS Exploits

Date Description
2011-08-12 Name : Ubuntu Update for linux-lts-backport-maverick USN-1187-1
File : nvt/gb_ubuntu_USN_1187_1.nasl
2011-07-18 Name : Ubuntu Update for linux-ec2 USN-1161-1
File : nvt/gb_ubuntu_USN_1161_1.nasl
2011-05-06 Name : SuSE Update for kernel SUSE-SA:2011:020
File : nvt/gb_suse_2011_020.nasl

Open Source Vulnerability Database (OSVDB)

Id Description
69003 Linux Kernel KVM Memory arch/x86/kvm/x86.c Multiple Function Memory Content D...

Linux Kernel contains a flaw that may lead to an unauthorized information disclosure.  The 'kvm_vcpu_ioctl_x86_get_vcpu_events()', 'kvm_vcpu_ioctl_x86_get_debugregs()', 'kvm_vm_ioctl_get_pit2()' and 'kvm_arch_vm_ioctl()' functions in 'arch/x86/kvm/x86.c' do not properly initialize all fields. This can be exploited to disclose kernel stack memory to a local attacker.

Nessus® Vulnerability Scanner

Date Description
2014-06-13 Name : The remote openSUSE host is missing a security update.
File : suse_11_3_kernel-110414.nasl - Type : ACT_GATHER_INFO
2013-07-12 Name : The remote Oracle Linux host is missing one or more security updates.
File : oraclelinux_ELSA-2010-0998.nasl - Type : ACT_GATHER_INFO
2013-03-08 Name : The remote Ubuntu host is missing one or more security-related patches.
File : ubuntu_USN-1093-1.nasl - Type : ACT_GATHER_INFO
2013-01-24 Name : The remote Red Hat host is missing one or more security updates.
File : redhat-RHSA-2010-0998.nasl - Type : ACT_GATHER_INFO
2013-01-24 Name : The remote Red Hat host is missing one or more security updates.
File : redhat-RHSA-2011-0883.nasl - Type : ACT_GATHER_INFO
2012-08-01 Name : The remote Scientific Linux host is missing one or more security updates.
File : sl_20101220_kvm_on_SL5_x.nasl - Type : ACT_GATHER_INFO
2011-12-13 Name : The remote SuSE 11 host is missing one or more security updates.
File : suse_11_kernel-110823.nasl - Type : ACT_GATHER_INFO
2011-12-13 Name : The remote SuSE 11 host is missing one or more security updates.
File : suse_11_kernel-110824.nasl - Type : ACT_GATHER_INFO
2011-08-09 Name : The remote Ubuntu host is missing one or more security-related patches.
File : ubuntu_USN-1187-1.nasl - Type : ACT_GATHER_INFO
2011-07-14 Name : The remote Ubuntu host is missing a security-related patch.
File : ubuntu_USN-1161-1.nasl - Type : ACT_GATHER_INFO
2011-05-20 Name : The remote Red Hat host is missing one or more security updates.
File : redhat-RHSA-2011-0542.nasl - Type : ACT_GATHER_INFO
2011-02-02 Name : The remote Ubuntu host is missing one or more security-related patches.
File : ubuntu_USN-1054-1.nasl - Type : ACT_GATHER_INFO
2011-01-21 Name : The remote SuSE 11 host is missing one or more security updates.
File : suse_11_kernel-110104.nasl - Type : ACT_GATHER_INFO

Alert History

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0
Date Informations
2014-02-17 11:54:11
  • Multiple Updates