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.
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
| Link | Tags |
|---|---|
| http://www.oracle.com/technetwork/topics/security/ovmbulletinjul2016-3090546.html | third party advisory |
| http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181699.html | vendor advisory mailing list third party advisory |
| http://xenbits.xen.org/xsa/advisory-172.html | patch vendor advisory |
| http://www.securityfocus.com/bid/85716 | third party advisory vdb entry |
| http://lists.fedoraproject.org/pipermail/package-announce/2016-April/181729.html | vendor advisory mailing list third party advisory |
| http://xenbits.xen.org/xsa/xsa172.patch | patch vendor advisory |
| http://www.securitytracker.com/id/1035435 | third party advisory vdb entry |
| http://support.citrix.com/article/CTX209443 | third party advisory |
| http://www.debian.org/security/2016/dsa-3554 | third party advisory vendor advisory |