{"cve":"CVE-2021-28702","nvd":{"published":"2021-10-06T14:15:07.230","modified":"2026-06-17T03:46:50.030","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H","score":7.6},"cwes":["CWE-269"],"references":["http://www.openwall.com/lists/oss-security/2021/10/07/2","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OIHEJ3R3EH5DYI2I5UMD2ULJ2ELA3EX/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FDPRMOBBLS74ONYP3IXZZXSTLKR7GRQB/","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TRAWV6PO2KUGVZTESERECOBUBZ6X45I7/","https://security.gentoo.org/glsa/202208-23"],"products":["debian:debian_linux","fedoraproject:fedora","xen:xen"],"source":"nvd","synced_at":"2026-10-19T21:23:41.316049955+00:00"},"epss":{"cve":"CVE-2021-28702","score":0.00441,"percentile":0.38377,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}