Vulnerability Name:

CVE-2018-18021 (CCN-150991)

Assigned:2018-10-02
Published:2018-10-02
Updated:2019-04-03
Summary:arch/arm64/kvm/guest.c in KVM in the Linux kernel before 4.18.12 on the arm64 platform mishandles the KVM_SET_ON_REG ioctl. This is exploitable by attackers who can create virtual machines. An attacker can arbitrarily redirect the hypervisor flow of control (with full register control). An attacker can also cause a denial of service (hypervisor panic) via an illegal exception return. This occurs because of insufficient restrictions on userspace access to the core register file, and because PSTATE.M validation does not prevent unintended execution modes.
CVSS v3 Severity:7.1 High (CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H)
6.2 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): High
Availibility (A): High
4.4 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H)
3.9 Low (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): High
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): High
CVSS v2 Severity:3.6 Low (CVSS v2 Vector: AV:L/AC:L/Au:N/C:N/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): Partial
4.6 Medium (CCN CVSS v2 Vector: AV:L/AC:L/Au:S/C:N/I:N/A:C)
Exploitability Metrics:Access Vector (AV): Local
Access Complexity (AC): Low
Athentication (Au): Single_Instance
Impact Metrics:Confidentiality (C): None
Integrity (I): None
Availibility (A): Complete
Vulnerability Type:CWE-20
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2018-18021

Source: MISC
Type: Patch
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2a3f93459d689d990b3ecfbe782fec89b97d3279

Source: MISC
Type: Patch
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d26c25a9d19b5976b319af528886f89cf455692d

Source: BID
Type: Third Party Advisory, VDB Entry
105550

Source: CCN
Type: BID-105550
Linux Kernel 'arch/arm64/kvm/guest.c' Local Privilege Escalation Vulnerability

Source: REDHAT
Type: Third Party Advisory
RHSA-2018:3656

Source: MISC
Type: Patch
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.12

Source: XF
Type: UNKNOWN
linux-kernel-cve201818021-dos(150991)

Source: CCN
Type: Linux Kernel GIT Repository
arm64: KVM: Sanitize PSTATE.M when being set from userspace

Source: MISC
Type: Patch
https://github.com/torvalds/linux/commit/2a3f93459d689d990b3ecfbe782fec89b97d3279

Source: MISC
Type: Patch
https://github.com/torvalds/linux/commit/d26c25a9d19b5976b319af528886f89cf455692d

Source: UBUNTU
Type: Third Party Advisory
USN-3821-1

Source: UBUNTU
Type: Third Party Advisory
USN-3821-2

Source: UBUNTU
Type: UNKNOWN
USN-3931-1

Source: UBUNTU
Type: UNKNOWN
USN-3931-2

Source: DEBIAN
Type: Third Party Advisory
DSA-4313

Source: CCN
Type: oss-sec Mailing List, Tue, 2 Oct 2018 17:07:14 +0100
arm64 Linux kernel: Privilege escalation by taking control of the KVM hypervisor

Source: MISC
Type: Mailing List, Patch, Third Party Advisory
https://www.openwall.com/lists/oss-security/2018/10/02/2

Vulnerable Configuration:Configuration 1:
  • cpe:/o:linux:linux_kernel:*:*:*:*:*:*:*:* (Version < 4.18.12)

    • Configuration 2:
  • cpe:/o:debian:debian_linux:9.0:*:*:*:*:*:*:*

    • Configuration 3:
  • cpe:/o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
  • OR cpe:/o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*

    • Configuration CCN 1:
  • cpe:/o:linux:linux_kernel:4.18.11:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    Oval Definitions
    Definition IDClassTitleLast Modified
    oval:com.ubuntu.bionic:def:201818021000
    V
    		CVE-2018-18021 on Ubuntu 18.04 LTS (bionic) - medium.
    2018-10-07
    oval:com.ubuntu.cosmic:def:2018180210000000
    V
    		CVE-2018-18021 on Ubuntu 18.10 (cosmic) - medium.
    2018-10-07
    oval:com.ubuntu.cosmic:def:201818021000
    V
    		CVE-2018-18021 on Ubuntu 18.10 (cosmic) - medium.
    2018-10-07
    oval:com.ubuntu.bionic:def:2018180210000000
    V
    		CVE-2018-18021 on Ubuntu 18.04 LTS (bionic) - medium.
    2018-10-07
    oval:com.ubuntu.trusty:def:201818021000
    V
    		CVE-2018-18021 on Ubuntu 14.04 LTS (trusty) - medium.
    2018-10-07
    oval:com.ubuntu.xenial:def:2018180210000000
    V
    		CVE-2018-18021 on Ubuntu 16.04 LTS (xenial) - medium.
    2018-10-07
    oval:com.ubuntu.xenial:def:201818021000
    V
    		CVE-2018-18021 on Ubuntu 16.04 LTS (xenial) - medium.
    2018-10-07
    BACK
    linux linux kernel *
    debian debian linux 9.0
    canonical ubuntu linux 14.04
    canonical ubuntu linux 16.04
    linux linux kernel 4.18.11