CVE-2018-18021

LOW

Description

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.

References

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

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d26c25a9d19b5976b319af528886f89cf455692d

http://www.securityfocus.com/bid/105550

https://access.redhat.com/errata/RHSA-2018:3656

https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.12

https://github.com/torvalds/linux/commit/2a3f93459d689d990b3ecfbe782fec89b97d3279

https://github.com/torvalds/linux/commit/d26c25a9d19b5976b319af528886f89cf455692d

https://usn.ubuntu.com/3821-1/

https://usn.ubuntu.com/3821-2/

https://www.debian.org/security/2018/dsa-4313

https://www.openwall.com/lists/oss-security/2018/10/02/2

Details

Source: MITRE

Published: 2018-10-07

Updated: 2018-11-27

Type: CWE-20

Risk Information

CVSS v2.0

Base Score: 3.6

Vector: AV:L/AC:L/Au:N/C:N/I:P/A:P

Impact Score: 4.9

Exploitability Score: 3.9

Severity: LOW

CVSS v3.0

Base Score: 7.1

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H

Impact Score: 5.2

Exploitability Score: 1.8

Severity: HIGH