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CVE-2021-28704 Detail

Current Description

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).


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  8.8 HIGH
Vector:  CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT/ Mailing List  Third Party Advisory 
https://xenbits.xenproject.org/xsa/advisory-388.txt Patch  Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-77 Improper Neutralization of Special Elements used in a Command ('Command Injection') cwe source acceptance level NIST  

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-28704
NVD Published Date:
11/23/2021
NVD Last Modified:
12/01/2021
Source:
Xen Project