The remote Debian host is missing a security-related update.
Multiple vulnerabilities have been discovered in the Xen hypervisor : - CVE-2017-10912 Jann Horn discovered that incorrectly handling of page transfers might result in privilege escalation. - CVE-2017-10913 / CVE-2017-10914 Jann Horn discovered that race conditions in grant handling might result in information leaks or privilege escalation. - CVE-2017-10915 Andrew Cooper discovered that incorrect reference counting with shadow paging might result in privilege escalation. - CVE-2017-10916 Andrew Cooper discovered an information leak in the handling of the Memory Protection Extensions (MPX) and Protection Key (PKU) CPU features. This only affects Debian stretch. - CVE-2017-10917 Ankur Arora discovered a NULL pointer dereference in event polling, resulting in denial of service. - CVE-2017-10918 Julien Grall discovered that incorrect error handling in physical-to-machine memory mappings may result in privilege escalation, denial of service or an information leak. - CVE-2017-10919 Julien Grall discovered that incorrect handling of virtual interrupt injection on ARM systems may result in denial of service. - CVE-2017-10920 / CVE-2017-10921 / CVE-2017-10922 Jan Beulich discovered multiple places where reference counting on grant table operations was incorrect, resulting in potential privilege escalation. - CVE-2017-12135 Jan Beulich found multiple problems in the handling of transitive grants which could result in denial of service and potentially privilege escalation. - CVE-2017-12136 Ian Jackson discovered that race conditions in the allocator for grant mappings may result in denial of service or privilege escalation. This only affects Debian stretch. - CVE-2017-12137 Andrew Cooper discovered that incorrect validation of grants may result in privilege escalation. - CVE-2017-12855 Jan Beulich discovered that incorrect grant status handling, thus incorrectly informing the guest that the grant is no longer in use. - XSA-235 (no CVE yet) Wei Liu discovered that incorrect locking of add-to-physmap operations on ARM may result in denial of service.
Upgrade the xen packages. For the oldstable distribution (jessie), these problems have been fixed in version 4.4.1-9+deb8u10. For the stable distribution (stretch), these problems have been fixed in version 4.8.1-1+deb9u3.