CVE-2021-28697

 

Published at: - 27-08-2021 09:15

Last modified: - 28-09-2022 09:56

Total changes: - 11

Description

grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.

Common Vulnerability Scoring System (CVSS)

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

 

Verification logic

 

Reference

• https://xenbits.xenproject.org/xsa/advisory-379.txt
• FEDORA-2021-d68ed12e46-Mailing List, Third Party Advisory
• FEDORA-2021-4f129cc0c1-Mailing List, Third Party Advisory
• DSA-4977-Third Party Advisory
• FEDORA-2021-081f9bf5d2-Mailing List, Third Party Advisory
• GLSA-202208-23-Third Party Advisory

 

Keywords

NVD

 

CVE-2021-28697

 

CVE

 

Common vulnerabilities & exposures

 

CVSS

 

Common vulnerability scoring system

 

Security

 

Vulnerabilities

 

Exposures