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CVE-2021-28703

Опубликовано: 07 дек. 2021
Источник: ubuntu
Приоритет: medium
CVSS2: 6.9
CVSS3: 7

Описание

grant table v2 status pages may remain accessible after de-allocation (take two) 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. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.

РелизСтатусПримечание
bionic

ignored

end of standard support, was needs-triage
devel

needs-triage

esm-apps/focal

needs-triage

esm-apps/jammy

needs-triage

esm-apps/noble

needs-triage

esm-infra-legacy/trusty

DNE

esm-infra/bionic

needs-triage

esm-infra/xenial

needs-triage

focal

ignored

end of standard support, was needs-triage
hirsute

ignored

end of life

Показывать по

6.9 Medium

CVSS2

7 High

CVSS3

Связанные уязвимости

CVSS3: 7
nvd
около 4 лет назад

grant table v2 status pages may remain accessible after de-allocation (take two) 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. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.

CVSS3: 7
debian
около 4 лет назад

grant table v2 status pages may remain accessible after de-allocation ...

CVSS3: 7
github
около 4 лет назад

grant table v2 status pages may remain accessible after de-allocation (take two) 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. This bug was fortuitously fixed by code cleanup in Xen 4.14, and backported to security-supported Xen branches as a prerequisite of the fix for XSA-378.

suse-cvrf
около 4 лет назад

Security update for xen

6.9 Medium

CVSS2

7 High

CVSS3