CVE-2021-28702

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.

Category

7.6
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.07%
Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory debian.org Vendor Advisory gentoo.org Vendor Advisory xenproject.org
Affected: Xen xen
Published at:
Updated at:

References

Link Tags
https://xenbits.xenproject.org/xsa/advisory-386.txt vendor advisory
http://www.openwall.com/lists/oss-security/2021/10/07/2 third party advisory mailing list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TRAWV6PO2KUGVZTESERECOBUBZ6X45I7/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FDPRMOBBLS74ONYP3IXZZXSTLKR7GRQB/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OIHEJ3R3EH5DYI2I5UMD2ULJ2ELA3EX/ vendor advisory
https://www.debian.org/security/2021/dsa-5017 third party advisory vendor advisory
https://security.gentoo.org/glsa/202208-23 third party advisory vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-28702?
CVE-2021-28702 has been scored as a high severity vulnerability.
How to fix CVE-2021-28702?
To fix CVE-2021-28702, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-28702 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-28702 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-28702?
CVE-2021-28702 affects Xen xen.
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