CVE-2016-3158

low-risk

Published 2016-04-13

The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076.

Do I need to act?

0.04% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 3.8/10 Low

LOCAL / LOW complexity

Affected Products (5)

Vm Server

Xen

Fedora

Affected Vendors

Fedoraproject Xen Oracle

References (20)

Third Party Advisory http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181699.html

Third Party Advisory http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181729.html

http://support.citrix.com/article/CTX209443

http://www.debian.org/security/2016/dsa-3554

Vendor Advisory http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.htm...

Third Party Advisory http://www.securityfocus.com/bid/85714

Third Party Advisory http://www.securitytracker.com/id/1035435

Vendor Advisory http://xenbits.xen.org/xsa/advisory-172.html

Patch http://xenbits.xen.org/xsa/xsa172-4.3.patch

Patch http://xenbits.xen.org/xsa/xsa172.patch