Xen 4.7 allows local guest OS users to obtain sensitive host information by loading a 32-bit ELF symbol table.
https://security.gentoo.org/glsa/201612-56
https://euvd.enisa.europa.eu/vulnerability/EUVD-2016-10194
http://xenbits.xen.org/xsa/xsa194.patch
http://xenbits.xen.org/xsa/advisory-194.html