National Vulnerability Database

National Vulnerability Database

National Vulnerability
Database

CVE-2019-18425 Detail

Current Description

An issue was discovered in Xen through 4.12.x allowing 32-bit PV guest OS users to gain guest OS privileges by installing and using descriptors. There is missing descriptor table limit checking in x86 PV emulation. When emulating certain PV guest operations, descriptor table accesses are performed by the emulating code. Such accesses should respect the guest specified limits, unless otherwise guaranteed to fail in such a case. Without this, emulation of 32-bit guest user mode calls through call gates would allow guest user mode to install and then use descriptors of their choice, as long as the guest kernel did not itself install an LDT. (Most OSes don't install any LDT by default). 32-bit PV guest user mode can elevate its privileges to that of the guest kernel. Xen versions from at least 3.2 onwards are affected. Only 32-bit PV guest user mode can leverage this vulnerability. HVM, PVH, as well as 64-bit PV guests cannot leverage this vulnerability. Arm systems are unaffected.

Source:  MITRE
View Analysis Description

Severity



CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score: 9.8 CRITICAL
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

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Hyperlink Resource
http://www.openwall.com/lists/oss-security/2019/10/31/2 Mailing List Third Party Advisory
http://xenbits.xen.org/xsa/advisory-298.html Patch Vendor Advisory

Weakness Enumeration

CWE-ID CWE Name Source
CWE-269 Improper Privilege Management NIST  

Known Affected Software Configurations Switch to CPE 2.2

Configuration 1 ( hide )
 cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
     Show Matching CPE(s)
Up to (including)
4.12.1


Change History

2 change records found - show changes

Quick Info

CVE Dictionary Entry:
CVE-2019-18425
NVD Published Date:
10/31/2019
NVD Last Modified:
11/06/2019