CVE-2016-3159
The fpu_fxrstor function in arch/x86/i387.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…
Does this matter?
Lower severity and a low EPSS score (0.40%). Track it; it rarely justifies an emergency change on its own.
Description
The fpu_fxrstor function in arch/x86/i387.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.
- CVSS 3.0
- 3.8 LOWCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:N/A:N
- EPSS
- 0.40% probability · 34th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-200, CWE-284
- Affected
- oracle/vm server · xen/xen · fedoraproject/fedora · debian/debian linux
- Source
- cve@mitre.org
EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181699.htmlMailing List, Third Party Advisory
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181729.htmlMailing List, Third Party Advisory
- http://support.citrix.com/article/CTX209443Third Party Advisory
- http://www.debian.org/security/2016/dsa-3554Third Party Advisory
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.htmlThird Party Advisory
- http://www.securityfocus.com/bid/85716Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1035435Third Party Advisory, VDB Entry
- http://xenbits.xen.org/xsa/advisory-172.htmlPatch, Vendor Advisory
- http://xenbits.xen.org/xsa/xsa172.patchPatch, Vendor Advisory
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181699.htmlMailing List, Third Party Advisory
- http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181729.htmlMailing List, Third Party Advisory
- http://support.citrix.com/article/CTX209443Third Party Advisory
- http://www.debian.org/security/2016/dsa-3554Third Party Advisory
- http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.htmlThird Party Advisory
- http://www.securityfocus.com/bid/85716Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1035435Third Party Advisory, VDB Entry
- http://xenbits.xen.org/xsa/advisory-172.htmlPatch, Vendor Advisory
- http://xenbits.xen.org/xsa/xsa172.patchPatch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.