CVE-2021-28702

high

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.

References

https://xenbits.xenproject.org/xsa/advisory-386.txt

http://www.openwall.com/lists/oss-security/2021/10/07/2

https://lists.fedoraproject.org/archives/list/[email protected]/message/FDPRMOBBLS74ONYP3IXZZXSTLKR7GRQB/

https://lists.fedoraproject.org/archives/list/[email protected]/message/TRAWV6PO2KUGVZTESERECOBUBZ6X45I7/

https://lists.fedoraproject.org/archives/list/[email protected]/message/2OIHEJ3R3EH5DYI2I5UMD2ULJ2ELA3EX/

https://www.debian.org/security/2021/dsa-5017

https://security.gentoo.org/glsa/202208-23

Details

Source: MITRE

Published: 2021-10-06

Updated: 2022-10-29

Type: CWE-269

Risk Information

CVSS v2

Base Score: 4.6

Vector: AV:L/AC:L/Au:N/C:P/I:P/A:P

Impact Score: 6.4

Exploitability Score: 3.9

Severity: MEDIUM

CVSS v3

Base Score: 7.6

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

Impact Score: 6

Exploitability Score: 0.9

Severity: HIGH