| CVE-2021-28702 | Date: (C)2021-10-07 (M)2024-02-09 |
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 Score and Metrics +CVSS Score and Metrics -| CVSS V3 Severity: | CVSS V2 Severity: |
| CVSS Score : 7.6 | CVSS Score : 4.6 |
| Exploit Score: 0.9 | Exploit Score: 3.9 |
| Impact Score: 6.0 | Impact Score: 6.4 |
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| CVSS V3 Metrics: | CVSS V2 Metrics: |
| Attack Vector: PHYSICAL | Access Vector: LOCAL |
| Attack Complexity: LOW | Access Complexity: LOW |
| Privileges Required: NONE | Authentication: NONE |
| User Interaction: NONE | Confidentiality: PARTIAL |
| Scope: CHANGED | Integrity: PARTIAL |
| Confidentiality: HIGH | Availability: PARTIAL |
| Integrity: HIGH | |
| Availability: HIGH | |
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