Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Physical
0

CVE-2021-28702

Disclosure Date: October 06, 2021
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via Reserved Memory Region Reporting, “RMRR”). These are typically used for platform tasks such as legacy USB emulation. If such a device is passed through to a guest, then on guest shutdown the device is not properly deassigned. The IOMMU configuration for these devices which are not properly deassigned ends up pointing to a freed data structure, including the IO Pagetables. Subsequent DMA or interrupts from the device will have unpredictable behaviour, ranging from IOMMU faults to memory corruption.

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CVSS V3 Severity and Metrics
Base Score:
7.6 High
Impact Score:
6
Exploitability Score:
0.9
Vector:
CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Attack Vector (AV):
Physical
Attack Complexity (AC):
Low
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Changed
Confidentiality (C):
High
Integrity (I):
High
Availability (A):
High

General Information

Vendors

  • debian,
  • fedoraproject,
  • xen

Products

  • debian linux 9.0,
  • fedora 33,
  • fedora 34,
  • fedora 35,
  • xen
Technical Analysis