Memory Management Flaw in Xen Hypervisor Affects Guest Virtualization
CVE-2021-28703

7HIGH

Key Information:

Vendor

Xen Project
Status
Xen
Vendor
CVE Published:
7 December 2021

What is CVE-2021-28703?

A vulnerability in the Xen Hypervisor's memory management system allows guests to retain access to freed grant table v2 status pages. This occurs when guests transition from v2 to v1, causing the hypervisor to lose track of specific mappings. The flaw, which can lead to unauthorized access to Xen-owned memory pages, can allow malicious actors to exploit these pages for unintended purposes. The issue was addressed in Xen 4.14 and has been backported to other security-supported branches to enhance system integrity.

Affected Version(s)

Xen Branch 4.13 <= 4.13

Xen Branch 4.13.4 4.13.4

Xen Branch 4.14.x 4.14.x

References

https://xenbits.xenproject.org/xsa/advisory-387.txt
https://security.gentoo.org/glsa/202402-07
vendor-advisory

CVSS V3.1

Score:
7
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
High
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

{'credit_data': {'description': {'description_data': [{'lang': 'eng', 'value': 'This issue was discovered by Patryk Balicki and Julien Grall of Amazon.'}]}}}
.