CVE-2016-4480

Description

The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen 4.6.x and earlier does not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might allow local guest OS users to gain privileges via a crafted mapping of memory.

CVSS Metrics

• v3.0•HIGH•Score: 8.4CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
• v2.0•HIGH•Score: 7.2AV:L/AC:L/Au:N/C:C/I:C/A:C

EPSS Trends

Current EPSS score: 0.39%• Percentile: 61%

Techniques & Countermeasures

• CWE-264•Permissions, Privileges, and Access Controls

  Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.

Affected Systems

• oracle•vm_server

  3.2 | 3.3 | 3.4

• xen•xen

  ≤ 4.6.1

References (5)

• http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html
• http://www.securityfocus.com/bid/90710
• http://www.securitytracker.com/id/1035901
• http://www.debian.org/security/2016/dsa-3633
• http://xenbits.xen.org/xsa/advisory-176.html