CVE-2016-7777

MEDIUM

Xen < 4.7.0 - Race Condition

Title source: rule

Description

Xen 4.7.x and earlier does not properly honor CR0.TS and CR0.EM, which allows local x86 HVM guest OS users to read or modify FPU, MMX, or XMM register state information belonging to arbitrary tasks on the guest by modifying an instruction while the hypervisor is preparing to emulate it.

References (5)

[Third Party Advisory, VDB Entry] http://www.securityfocus.com/bid/93344

[Third Party Advisory, VDB Entry] http://www.securitytracker.com/id/1036942

[Mitigation, Patch, Vendor Advisory] http://xenbits.xen.org/xsa/advisory-190.html

[Vendor Advisory] https://support.citrix.com/article/CTX217363

[Third Party Advisory] https://security.gentoo.org/glsa/201611-09

Scores

CVSS v3 6.3

EPSS 0.0012

EPSS Percentile 31.1%

Attack Vector LOCAL

CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Classification

CWE

CWE-362

Status published

Affected Products (2)

xen/xen < 4.7.0

n/a/n/a

Timeline

Published Oct 07, 2016

Tracked Since Feb 18, 2026