4.4 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:P/I:P/A:P
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
0.0004 Low
EPSS
Percentile
14.2%
Another race in XENMAPSPACE_grant_table handling Guests are 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, are de-allocated when a guest switches
(back) from v2 to v1. Freeing such pages requires that the hypervisor
enforce that no parallel request can result in the addition of a mapping of
such a page to a guest. That enforcement was missing, allowing guests to
retain access to pages that were freed and perhaps re-used for other
purposes. Unfortunately, when XSA-379 was being prepared, this similar
issue was not noticed.
Author | Note |
---|---|
mdeslaur | hypervisor packages are in universe. For issues in the hypervisor, add appropriate tags to each section, ex: Tags_xen: universe-binary |
www.openwall.com/lists/oss-security/2021/09/08/2
xenbits.xen.org/xsa/advisory-384.html
launchpad.net/bugs/cve/CVE-2021-28701
nvd.nist.gov/vuln/detail/CVE-2021-28701
security-tracker.debian.org/tracker/CVE-2021-28701
www.cve.org/CVERecord?id=CVE-2021-28701
xenbits.xen.org/xsa/advisory-384.html
xenbits.xenproject.org/xsa/advisory-384.txt
4.4 Medium
CVSS2
Attack Vector
LOCAL
Attack Complexity
MEDIUM
Authentication
NONE
Confidentiality Impact
PARTIAL
Integrity Impact
PARTIAL
Availability Impact
PARTIAL
AV:L/AC:M/Au:N/C:P/I:P/A:P
7.8 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
0.0004 Low
EPSS
Percentile
14.2%