PCI devices with RMRRs not deassigned correctly Certain PCI devices in a system might be assigned Reserved Memory Regions (specified via…

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.

Scores

EPSS (exploitation in 30 days)

0.44% · top 61% of all CVEs (6 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.6.

Weakness

• unknown
• CWE-269 (opens in a new tab)All about CWE-269 and its CVEs

Affected products

• Xen · xen

  • unknown unspecified – < 4.12
  • affected 4.12.x – < unspecified
  • unaffected next of xen-unstable – < unspecified

References (7)

• https://xenbits.xenproject.org/xsa/advisory-386.txt (opens in a new tab)x_refsource_MISCx_transferred
• [oss-security] 20211007 Xen Security Advisory 386 v2 (CVE-2021-28702) - PCI devices with RMRRs not deassigned correctly (opens in a new tab)mailing-listx_refsource_MLISTx_transferred
• FEDORA-2021-80bbe7def0 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
• FEDORA-2021-0b7a484688 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
• FEDORA-2021-829f5f2f43 (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
• DSA-5017 (opens in a new tab)vendor-advisoryx_refsource_DEBIANx_transferred
• GLSA-202208-23 (opens in a new tab)vendor-advisoryx_refsource_GENTOOx_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2021-28702](https://trackcve.app/badge/CVE-2021-28702.svg)](https://trackcve.app/cve/CVE-2021-28702)

Record last updated 3 Aug 2024, 21:47 UTC.