8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
6.9 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
0.001 Low
EPSS
Percentile
26.8%
PoD operations on misaligned GFNs T[his CNA information record relates to
multiple CVEs; the text explains which aspects/vulnerabilities correspond
to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand
(PoD) mode, to provide a way for them to later easily have more memory
assigned. Guests are permitted to control certain P2M aspects of individual
pages via hypercalls. These hypercalls may act on ranges of pages specified
via page orders (resulting in a power-of-2 number of pages). The
implementation of some of these hypercalls for PoD does not enforce the
base page frame number to be suitably aligned for the specified order, yet
some code involved in PoD handling actually makes such an assumption. These
operations are XENMEM_decrease_reservation (CVE-2021-28704) and
XENMEM_populate_physmap (CVE-2021-28707), the latter usable only by domains
controlling the guest, i.e. a de-privileged qemu or a stub domain. (Patch
1, combining the fix to both these two issues.) In addition handling of
XENMEM_decrease_reservation can also trigger a host crash when the
specified page order is neither 4k nor 2M nor 1G (CVE-2021-28708, patch 2).
Author | Note |
---|---|
mdeslaur | hypervisor packages are in universe. For issues in the hypervisor, add appropriate tags to each section, ex: Tags_xen: universe-binary |
8.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
6.9 Medium
CVSS2
Access Vector
LOCAL
Access Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:M/Au:N/C:C/I:C/A:C
0.001 Low
EPSS
Percentile
26.8%