PT-2016-1714 · Amd+1 · Xen+1

Jan Beulich · Published 2016-04-13 · Updated 2017-01-09 · CVE-2016-3158

Positive Technologies (AI Summary)

CVSS v3.1

3.8

Low

Base vector

AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N

Name of the Vulnerable Software and Affected Versions Xen versions 4.x

Description The issue is related to the xrstor function in Xen, which does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors. This allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits, such as the exception mask bit. The problem is due to an incorrect fix for a previous issue.

Recommendations For Xen version 4.x, consider disabling the xrstor function as a temporary workaround until a patch is available. Restrict access to sensitive register content information to minimize the risk of exploitation.

Fix

Improper Access Control

Information Disclosure

Weakness Enumeration

CWE-284

CWE-200

Related Identifiers

BDU:2016-01040

CVE-2016-3158

DLA-571-1

DSA-3554-1

MGASA-2017-0012

OPENSUSE-SU-2016_2494-1

OPENSUSE-SU-2016_2497-1

SUSE-SU-2016:2093-1

SUSE-SU-2016:2100-1

SUSE-SU-2016:2528-1

SUSE-SU-2016:2533-1

SUSE-SU-2016:2725-1

Affected Products

Suse

Xen

References · 165

• https://ubuntu.com/security/CVE-2016-3158 · Vendor Advisory
• http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181699.html · Vendor Advisory
• http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181729.html · Vendor Advisory
• http://debian.org/security/2016/dsa-3554 · Vendor Advisory
• http://xenbits.xen.org/xsa/xsa172.patch · Patch
• https://osv.dev/vulnerability/CVE-2016-3158 · Vendor Advisory
• http://xenbits.xen.org/xsa/xsa172-4.3.patch · Patch
• https://osv.dev/vulnerability/SUSE-SU-2016:2725-1 · Vendor Advisory
• https://osv.dev/vulnerability/DSA-3554-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2016:2533-1 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2016:2093-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2016-3158 · Security Note
• https://osv.dev/vulnerability/SUSE-SU-2016:2528-1 · Vendor Advisory
• https://advisories.mageia.org/MGASA-2017-0012.html · Security Note
• http://xenbits.xen.org/xsa/advisory-172.html · Vendor Advisory