CVE-2017-12154: High severity Linux Linux kernel vulnerability

Published Sep 13, 2017
·
Updated

Linux kernel built with the KVM virtualisation support(CONFIGKVM), with nested virtualisation(nVMX) feature enabled(nested=1), is vulnerable to a crash due to disabled external interrupts. As L2 guest could access(r/w) hardware CR8 register of the host(L0).

In a nested virtualisation setup, L2 guest user could use this flaw to potentially crash the host(L0) resulting in DoS.

Upstream patch -------------- -> https://git.kernel.org/linus/51aa68e7d57e3217192d88ce90fd5b8ef29ec94f

Reference: ---------- -> http://www.openwall.com/lists/oss-security/2017/09/26/3

Other sources

The preparevmcs02 function in arch/x86/kvm/vmx.c in the Linux kernel through 4.13.3 does not ensure that the "CR8-load exiting" and "CR8-store exiting" L0 vmcs02 controls exist in cases where L1 omits the "use TPR shadow" vmcs12 control, which allows KVM L2 guest OS users to obtain read and write access to the hardware CR8 register.

— Ubuntu

Affected Software

26 affected componentsFixes available
Linux Linux kernel<=4.13.3
ubuntu/linux<3.13.0-153.203
3.13.0-153.203
ubuntu/linux-lts-xenial<4.4.0-98.121~14.04.1
4.4.0-98.121~14.04.1
ubuntu/linux<4.4.0-98.121
4.4.0-98.121
ubuntu/linux-aws<4.4.0-1039.48
4.4.0-1039.48
ubuntu/linux-azure<4.13.0-1005.7
4.13.0-1005.7
ubuntu/linux-gcp<4.13.0-1002.5
4.13.0-1002.5
ubuntu/linux-gke<4.4.0-1033.33
4.4.0-1033.33
ubuntu/linux-hwe<4.13.0-32.35~16.04.1
4.13.0-32.35~16.04.1
ubuntu/linux-kvm<4.4.0-1009.14
4.4.0-1009.14
ubuntu/linux-raspi2<4.4.0-1076.84
4.4.0-1076.84
ubuntu/linux-snapdragon<4.4.0-1078.83
4.4.0-1078.83
ubuntu/linux-azure-fde*
ubuntu/linux-azure-fde-5.15*
ubuntu/linux-gke*
ubuntu/linux-raspi2*
ubuntu/linux-riscv*
ubuntu/linux-intel-iot-realtime*
ubuntu/linux-realtime*
ubuntu/linux-riscv*
ubuntu/linux-azure-6.11*
ubuntu/linux-gcp-6.11*
ubuntu/linux-hwe-6.11*
ubuntu/linux-lowlatency-hwe-6.11*
ubuntu/linux-raspi-realtime*
debian/linux
6.1.176-16.1.190-16.12.107-16.12.116-17.2.15-17.3.4-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 3.13.0-153.203
  2. Upgrade

    Upgrade ubuntu/linux-lts-xenial to a version that resolves this vulnerability.

    Fixed in 4.4.0-98.121~14.04.1
  3. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 4.4.0-98.121
  4. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 4.4.0-1039.48
  5. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 4.13.0-1005.7
  6. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 4.13.0-1002.5
  7. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 4.4.0-1033.33
  8. Upgrade

    Upgrade ubuntu/linux-hwe to a version that resolves this vulnerability.

    Fixed in 4.13.0-32.35~16.04.1
  9. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 4.4.0-1009.14
  10. Upgrade

    Upgrade ubuntu/linux-raspi2 to a version that resolves this vulnerability.

    Fixed in 4.4.0-1076.84
  11. Upgrade

    Upgrade ubuntu/linux-snapdragon to a version that resolves this vulnerability.

    Fixed in 4.4.0-1078.83
  12. Upgrade

    Upgrade debian/linux to a version that resolves this vulnerability.

    Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.4-1
  13. Upgrade

    Upgrade Linux kernel KVM to a version that resolves this vulnerability.

    Patch 51aa68e7d57e3217192d88ce90fd5b8ef29ec94f

Event History

Sep 13, 2017
Data Sourced
via Red Hat·11:11 AM
DescriptionSeverityAffected Software
Sep 26, 2017
CVE Published
via Ubuntu·12:00 AM
Data Sourced
via Ubuntu·12:00 AM
RemedyDescriptionSeverityAffected Software
Data Sourced
via OSV·12:00 AM
DescriptionSeverityAffected Software
CVE Published
via MITRE·05:00 AM
Data Sourced
via MITRE·05:00 AM
DescriptionWeakness
Data Sourced
via NVD·05:29 AM
RemedyDescriptionSeverityAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2017-12154?

CVE-2017-12154 has a high severity rating due to the potential for a crash in the KVM nested virtualization environment.

2

How do I fix CVE-2017-12154?

To fix CVE-2017-12154, update your Linux kernel to a version that is 5.10.223-1 or higher, or 6.1.119-1 or higher.

3

Which Linux kernel versions are vulnerable to CVE-2017-12154?

Linux kernel versions up to and including 4.13.3 are vulnerable to CVE-2017-12154.

4

What impact does CVE-2017-12154 have on KVM users?

CVE-2017-12154 can allow an L2 guest to crash the host by manipulating hardware CR8 register access due to disabled external interrupts.

5

Is nested virtualization in KVM safe after applying the fix for CVE-2017-12154?

Yes, applying the fix will mitigate the specific vulnerability in nested virtualization, enhancing its safety.

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