CVE Vulnerability

CVE-2021-28696

IOMMU page mapping issues on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Both AMD and Intel allow ACPI tables to specify regions of memory which should be left untranslated, which typically means these addresses should pass the translation phase unaltered. While these are typically device specific ACPI properties, they can also be specified to apply to a range of devices, or even all devices. On all systems with such regions Xen failed to prevent guests from undoing/replacing such mappings (CVE-2021-28694). On AMD systems, where a discontinuous range is specified by firmware, the supposedly-excluded middle range will also be identity-mapped (CVE-2021-28695). Further, on AMD systems, upon de-assigment of a physical device from a guest, the identity mappings would be left in place, allowing a guest continued access to ranges of memory which it shouldn't have access to anymore (CVE-2021-28696).

4.6 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 3.9 / Impact : 6.4

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

Scope

6.8 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 0.9 / Impact : 5.9

Attack Vector PHYSICAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://xenbits.xenproject.org/xsa/advisory-378.txt Vendor Advisory
http://www.openwall.com/lists/oss-security/2021/09/01/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/01/5 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2021/09/01/6 Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/ Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/ Mailing List Third Party Advisory
https://www.debian.org/security/2021/dsa-4977 Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/ Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202208-23 Third Party Advisory
Configurations

Configuration 1

cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
Information

Published : 2021-08-27 07:15

Updated : 2022-09-28 07:56

NVD link : CVE-2021-28696

Mitre link : CVE-2021-28696

Products Affected
No products.
CWE
CWE-863