This update for xen fixes several issues.
These security issues were fixed:
- CVE-2016-9637: ioport array overflow allowing a malicious guest administrator can escalate their privilege to that of the host (bsc#1011652)
- CVE-2016-9386: x86 null segments were not always treated as unusable allowing an unprivileged guest user program to elevate its privilege to that of the guest operating system. Exploit of this vulnerability is easy on Intel and more complicated on AMD (bsc#1009100)
- CVE-2016-9382: x86 task switch to VM86 mode was mis-handled, allowing a unprivileged guest process to escalate its privilege to that of the guest operating system on AMD hardware. On Intel hardware a malicious unprivileged guest process can crash the guest (bsc#1009103)
- CVE-2016-9383: The x86 64-bit bit test instruction emulation was broken, allowing a guest to modify arbitrary memory leading to arbitray code execution (bsc#1009107)
- CVE-2016-9381: Improper processing of shared rings allowing guest administrators take over the qemu process, elevating their privilege to that of the qemu process (bsc#1009109)
- CVE-2016-9380: Delimiter injection vulnerabilities in pygrub allowed guest administrators to obtain the contents of sensitive host files or delete the files (bsc#1009111)
- CVE-2016-9379: Delimiter injection vulnerabilities in pygrub allowed guest administrators to obtain the contents of sensitive host files or delete the files (bsc#1009111)
- CVE-2016-7777: Xen did not properly honor CR0.TS and CR0.EM, which allowed local x86 HVM guest OS users to read or modify FPU, MMX, or XMM register state information belonging to arbitrary tasks on the guest by modifying an instruction while the hypervisor is preparing to emulate it (bsc#1000106)
- CVE-2016-8910: The rtl8139_cplus_transmit function in hw/net/rtl8139.c allowed local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) by leveraging failure to limit the ring descriptor count...