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CVE-2018-18021

Publication date 7 October 2018

Last updated 24 July 2024

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.1 · High

Score breakdown

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.

From the Ubuntu Security Team

It was discovered that the KVM implementation in the Linux kernel on ARM 64bit processors did not properly handle some ioctls. An attacker with the privilege to create KVM-based virtual machines could use this to cause a denial of service (host system crash) or execute arbitrary code in the host.

Status

Package Ubuntu Release Status
linux 18.10 cosmic
Not affected
18.04 LTS bionic
Fixed 4.15.0-47.50
16.04 LTS xenial
Fixed 4.4.0-139.165
14.04 LTS trusty Ignored
linux-aws 18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-aws-hwe 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial
Fixed 4.15.0-1035.37~16.04.1
14.04 LTS trusty Not in release
linux-azure 18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
linux-azure-edge 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-euclid 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-flo 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-gcp 18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-gcp-edge 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-gke 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-goldfish 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-grouper 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-hwe 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial
Fixed 4.15.0-47.50~16.04.1
14.04 LTS trusty Not in release
linux-hwe-edge 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial
Fixed 4.15.0-47.50~16.04.1
14.04 LTS trusty Not in release
linux-kvm 18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty Not in release
linux-lts-trusty 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-utopic 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-vivid 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-wily 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-lts-xenial 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty
Fixed 4.4.0-139.165~14.04.1
linux-maguro 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-mako 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-manta 18.10 cosmic Not in release
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
linux-oem 18.10 cosmic
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial Ignored
14.04 LTS trusty Not in release
linux-oracle 18.10 cosmic
Not affected
18.04 LTS bionic
Fixed 4.15.0-1010.12
16.04 LTS xenial
Fixed 4.15.0-1010.12~16.04.1
14.04 LTS trusty Not in release
linux-raspi2 18.10 cosmic
Not affected
18.04 LTS bionic
Fixed 4.15.0-1033.35
16.04 LTS xenial
Fixed 4.4.0-1100.108
14.04 LTS trusty Not in release
linux-snapdragon 18.10 cosmic Not in release
18.04 LTS bionic
Not affected
16.04 LTS xenial
Fixed 4.4.0-1104.109
14.04 LTS trusty Not in release

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
linux

Severity score breakdown

Parameter Value
Base score 7.1 · High
Attack vector Local
Attack complexity Low
Privileges required Low
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact High
Availability impact High
Vector CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H