CVE-2019-18424

Current Description

An issue was discovered in Xen through 4.12.x allowing attackers to gain host OS privileges via DMA in a situation where an untrusted domain has access to a physical device. This occurs because passed through PCI devices may corrupt host memory after deassignment. When a PCI device is assigned to an untrusted domain, it is possible for that domain to program the device to DMA to an arbitrary address. The IOMMU is used to protect the host from malicious DMA by making sure that the device addresses can only target memory assigned to the guest. However, when the guest domain is torn down, or the device is deassigned, the device is assigned back to dom0, thus allowing any in-flight DMA to potentially target critical host data. An untrusted domain with access to a physical device can DMA into host memory, leading to privilege escalation. Only systems where guests are given direct access to physical devices capable of DMA (PCI pass-through) are vulnerable. Systems which do not use PCI pass-through are not vulnerable.

Referenced by CVEs:

CVE-2019-19579

Basic Data

Published	October 31, 2019
Last Modified	November 14, 2019
Assigner	cve@mitre.org
Data Type	CVE
Data Format	MITRE
Data Version	4.0
Problem Type	CWE-78
CVE Data Version	4.0

Base Metric V2

CVSS 2 - Version	2.0
CVSS 2 - Vector String	AV:L/AC:M/Au:N/C:C/I:C/A:C
CVSS 2 - Access Vector	LOCAL
CVSS 2 - Access Complexity	MEDIUM
CVSS 2 - Authentication	NONE
CVSS 2 - Confidentiality Impact	COMPLETE
CVSS 2 - Availability Impact	COMPLETE
CVSS 2 - Base Score	6.9
Severity	MEDIUM
Exploitability Score	3.4
Impact Score	10.0
Obtain All Privilege	false
Obtain User Privilege	false
Obtain Other Privilege	false

Base Metric V3

No data provided.

Configurations

Vulnerable Software List

Vendor	Product	Versions
Xen	Xen	*

References