Auth bypass in Linux Kernel

CVE-2019-3887

A flaw was found in the way KVM hypervisor handled x2APIC Machine Specific Rregister (MSR) access with nested(=1) virtualization enabled. In that, L1 guest could access L0's APIC register values via L2 guest, when 'virtualize x2APIC mode' is enabled. A guest could use this flaw to potentially crash the host kernel resulting in DoS issue. Kernel versions from 4.16 and newer are vulnerable to this issue.

Vulnerability class: Broken Access Control

EPSS: 0.004 (28.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.6 (Medium). Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-3887?
CVE-2019-3887 is a medium-severity vulnerability in Linux Kernel, classified under Incorrect Authorization. CVSS score: 5.6/10. Published 2019-04-09.
How severe is CVE-2019-3887?
Medium severity. CVSS v3 base score is 5.6 out of 10.