🛡️ CVE-2021-28702 on Debian — xen

⚪ Unknown ✅ No Known Exploit OSV
N/A
CVSS Score
0 Low4 Medium7 High9 Critical10

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.

Distribution advisory

This page covers CVE-2021-28702 as tracked by Debian, for the package xen. The fix is available in version 4.14.3+32-g9de3671772-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached with physical access to the device, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.

Affected software

DEBIAN-CVE-2021-28702 is recorded against 1 package.

  • xen (fixed in 4.14.3+32-g9de3671772-1)

Timeline and source

Published on 6 October 2021 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2021-28702 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Unknown
CVSS Score N/A
CVSS Vector CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source OSV
Published 2021-10-06
Updated 2026-08-12
Modified 2026-08-04
Fix URL N/A

Affected Packages

Software From version Fixed in
xen — 4.14.3+32-g9de3671772-1

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