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CVE-2021-28705

CVE information

Published

2 years ago

Last Modified

1 month ago

CVSSv2.0 Severity

Medium

CVSSv3.1 Severity

High

Impact Analysis

Description

issues with partially successful P2M updates on x86 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). In some cases the hypervisor carries out the requests by splitting them into smaller chunks. Error handling in certain PoD cases has been insufficient in that in particular partial success of some operations was not properly accounted for. There are two code paths affected - page removal (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix to both issues.).

CVSSv2.0 Score

Severity
Medium
Base Score
6.9/10
Exploit Score
3.4/10
Access Vector
Local
Access Complexity
Medium
Authentication Required
None
Impact Score
10/10
Confidentiality Impact
Complete
Availability Impact
Complete
Integrity Impact
Complete

CVSSv3.1 Score

Severity
High
Base Score
7.8/10
Exploit Score
1.8/10
Access Vector
Local
Access Complexity
Low
Privileges Required
Low
Impact Score
5.9/10
Confidentiality Impact
High
Availability Impact
High
Integrity Impact
High
Scope
Unchanged
User Interaction
None

Products Affected

CPE Affected Vulnerable Excluding Edit
cpe:2.3:o:xen:xen:4.15.0:*:*:*:*:*:x86:*
  Yes
- -
cpe:2.3:o:xen:xen:4.15.1:*:*:*:*:*:x86:*
  Yes
- -
cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
  Yes
4.14.0 -
cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
  Yes
4.13.0 -
cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
  Yes
3.4.0 -
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
  Yes
- -
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
  Yes
- -
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
  Yes
- -