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).
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: XEN

Published: 2021-08-27T18:46:33

Updated: 2024-08-03T21:47:33.195Z

Reserved: 2021-03-18T00:00:00

Link: CVE-2021-28696

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2021-08-27T19:15:07.633

Modified: 2024-11-21T06:00:09.800

Link: CVE-2021-28696

cve-icon Redhat

No data.