CVE-2018-15468 Information

Description

An issue was discovered in Xen through 4.11.x. The DEBUGCTL MSR contains several debugging features some of which virtualise cleanly but some do not. In particular Branch Trace Store is not virtualised by the processor and software has to be careful to configure it suitably not to lock up the core. As a result it must only be available to fully trusted guests. Unfortunately in the case that vPMU is disabled all value checking was skipped allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host causing a Denial of Service.

CVSS Vector

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

Reference

http://xenbits.xen.org/xsa/advisory-269.html https://security.gentoo.org/glsa/201810-06

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction Required

HIGH

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

6.0