CVE-2019-19579 Detail

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 (and assignable-add is not used), because of an incomplete fix for CVE-2019-18424. XSA-302 relies on the use of libxl's "assignable-add" feature to prepare devices to be assigned to untrusted guests. Unfortunately, this is not considered a strictly required step for device assignment. The PCI passthrough documentation on the wiki describes alternate ways of preparing devices for assignment, and libvirt uses its own ways as well. Hosts where these "alternate" methods are used will still leave the system in a vulnerable state after the device comes back from a guest. 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.


View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  6.8 MEDIUM
Vector:  CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have published a CVSS score for this CVE based on publicly available information at the time of analysis. The CNA has not provided a score within the CVE List.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to nvd@nist.gov.

Hyperlink Resource
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html
http://www.openwall.com/lists/oss-security/2019/12/05/7 Mailing List  Third Party Advisory 
http://xenbits.xen.org/xsa/advisory-306.html Vendor Advisory 
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RJYT5FNGM7JSVHHW6B22TSAATBOAPFPD/ Third Party Advisory 
https://seclists.org/bugtraq/2020/Jan/21
https://www.debian.org/security/2020/dsa-4602
https://www.openwall.com/lists/oss-security/2019/11/26/2 Mailing List  Third Party Advisory 
https://xenbits.xen.org/xsa/advisory-306.html Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-20 Improper Input Validation cwe source acceptance level NIST  

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

7 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2019-19579
NVD Published Date:
12/04/2019
NVD Last Modified:
01/13/2020
Source:
MITRE