CVE-2021-28702 - CVE House
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Status published High CVE-2021-28702

PCI devices with RMRRs not deassigned correctly Certain PCI devices...

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Affected Software

xen
Vulnerable Versions:
unspecified, 4.12.x, next of xen-unstable

Timeline

Official Publish: October 6th, 2021
Last Modified: August 3rd, 2024
Added to House: July 21st, 2026

CVSS Vectors

V3: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.