CVE-2021-28702
xen - security update
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.
How to fix CVE-2021-28702
To remediate CVE-2021-28702, upgrade the affected package to a fixed version below.
- —upgrade to 4.13.4-r1 or later
- —upgrade to 4.14.3+32-g9de3671772-1~deb11u1 or later
- —upgrade to 4.14.3+32-g9de3671772-1~deb11u1 or later
Is CVE-2021-28702 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 4.13.4-r1
- from 0, < 4.14.3+32-g9de3671772-1~deb11u1
- from 0, < 4.14.3+32-g9de3671772-1~deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.6 | CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |