The hvm_msr_read_intercept function in arch/x86/hvm/hvm.c in Xen 4.1 through 4.4.x uses an improper MSR range for x2APIC emulation, which allows local HVM guests to cause a denial of service (host crash) or read data from the hypervisor or other guests via unspecified vectors.

References

• https://nvd.nist.gov/vuln/detail/CVE-2014-7188
• https://exchange.xforce.ibmcloud.com/vulnerabilities/96785
• http://lists.fedoraproject.org/pipermail/package-announce/2014-October/140199.html
• http://lists.fedoraproject.org/pipermail/package-announce/2014-October/140418.html
• http://lists.fedoraproject.org/pipermail/package-announce/2014-October/140483.html
• http://lists.opensuse.org/opensuse-security-announce/2014-10/msg00002.html
• http://lists.opensuse.org/opensuse-security-announce/2014-10/msg00003.html
• http://secunia.com/advisories/61664
• http://secunia.com/advisories/61858
• http://secunia.com/advisories/61890
• http://security.gentoo.org/glsa/glsa-201412-42.xml
• http://support.citrix.com/article/CTX200218
• http://support.citrix.com/article/CTX201794
• http://www.c7zero.info/stuff/csw2017_ExploringYourSystemDeeper_updated.pdf
• http://www.debian.org/security/2014/dsa-3041
• http://www.securityfocus.com/bid/70198
• http://www.securitytracker.com/id/1030936
• http://xenbits.xen.org/xsa/advisory-108.html