7.8
CVSSv3

CVE-2021-28697

Published: 27/08/2021 Updated: 07/11/2023
CVSS v2 Base Score: 4.6 | Impact Score: 6.4 | Exploitability Score: 3.9
CVSS v3 Base Score: 7.8 | Impact Score: 5.9 | Exploitability Score: 1.8
VMScore: 410
Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P

Vulnerability Summary

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.

Vulnerability Trend

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xen xen

fedoraproject fedora 33

fedoraproject fedora 34

fedoraproject fedora 35

debian debian linux 11.0

Vendor Advisories

Multiple vulnerabilities have been discovered in the Xen hypervisor, which could result in privilege escalation, denial of service or information leaks With the end of upstream support for the 411 branch, the version of xen in the oldstable distribution (buster) is no longer supported If you rely on security support for your Xen installation an ...
No description is available for this CVE ...
Description of Problem Several security issues have been discovered in Citrix Hypervisor that, collectively, may allow privileged code in a guest VM to compromise or crash the hostThese issues have the following identifiers:  CVE-IDDescriptionPre-requisitesCVE-2021-28694Host denial of serviceMalicious privileged code execution in a guest VM r ...

Mailing Lists

<!--X-Body-Begin--> <!--X-User-Header--> oss-sec mailing list archives <!--X-User-Header-End--> <!--X-TopPNI--> By Date By Thread </form> <!--X-TopPNI-End--> <!--X-MsgBody--> <!--X-Subject-Header-Begin--> Xen Security Advisory 379 v2 (CVE-2021-28697) - grant table v2 status pages may remain accessible after de-allocation <!--X-Su ...