CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
12.6%
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.
OS | Version | Architecture | Package | Version | Filename |
---|---|---|---|---|---|
Debian | 12 | all | xen | < 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | xen_4.11.1~pre.20180911.5acdd26fdc+dfsg-2_all.deb |
Debian | 11 | all | xen | < 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | xen_4.11.1~pre.20180911.5acdd26fdc+dfsg-2_all.deb |
Debian | 999 | all | xen | < 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | xen_4.11.1~pre.20180911.5acdd26fdc+dfsg-2_all.deb |
Debian | 13 | all | xen | < 4.11.1~pre.20180911.5acdd26fdc+dfsg-2 | xen_4.11.1~pre.20180911.5acdd26fdc+dfsg-2_all.deb |
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:N/I:N/A:C
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H
EPSS
Percentile
12.6%