Misaligned Page Frame Vulnerability in Xen Hypervisor Affecting Multiple Guests
CVE-2021-28704

8.8HIGH

Key Information:

Vendor

Xen Project
Status
Xen
Vendor
CVE Published:
24 November 2021

What is CVE-2021-28704?

The vulnerability in the Xen Hypervisor allows x86 hardware virtual machines (HVM) and Paravirtualized hardware (PVH) guests to operate in a populate-on-demand (PoD) mode without proper alignment checks on the base page frame number. This defect can be exploited via hypercalls that handle memory management, particularly XENMEM_decrease_reservation and XENMEM_populate_physmap. This flaw may lead to incorrect memory mapping and potential host crashes if the page order does not conform to expected values, which can severely impact system integrity and stability.

Affected Version(s)

xen xen-unstable

xen 4.12.x

xen 4.15.x

References

https://xenbits.xenproject.org/xsa/advisory-388.txt
https://lists.fedoraproject.org/archives/list/package-ann...
vendor-advisory
https://www.debian.org/security/2021/dsa-5017
vendor-advisory

CVSS V3.1

Score:
8.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

{'credit_data': {'description': {'description_data': [{'lang': 'eng', 'value': 'This issue was discovered by Jan Beulich of SUSE.'}]}}}
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CVE-2021-28704 : Misaligned Page Frame Vulnerability in Xen Hypervisor Affecting Multiple Guests