FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

xen-kernel -- information leak in legacy x86 FPU/XMM initialization

Affected packages
xen-kernel < 4.5.2_1

Details

VuXML ID e839ca04-b40d-11e5-9728-002590263bf5
Discovery 2015-12-17
Entry 2016-01-06

The Xen Project reports:

When XSAVE/XRSTOR are not in use by Xen to manage guest extended register state, the initial values in the FPU stack and XMM registers seen by the guest upon first use are those left there by the previous user of those registers.

A malicious domain may be able to leverage this to obtain sensitive information such as cryptographic keys from another domain.

References

CVE Name CVE-2015-8555
FreeBSD PR ports/205841
URL http://xenbits.xen.org/xsa/advisory-165.html