- ------------------------------------------------------------------------- Debian Security Advisory DSA-3729-1 This email address is being protected from spambots. You need JavaScript enabled to view it. https://www.debian.org/security/ Salvatore Bonaccorso December 07, 2016 https://www.debian.org/security/faq - ------------------------------------------------------------------------- Package : xen CVE ID : CVE-2016-7777 CVE-2016-9379 CVE-2016-9380 CVE-2016-9382 CVE-2016-9383 CVE-2016-9385 CVE-2016-9386 Debian Bug : 845663 845664 845665 845668 845670 Multiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems: CVE-2016-7777 (XSA-190) Jan Beulich from SUSE discovered that Xen does not properly honor CR0.TS and CR0.EM for x86 HVM guests, potentially allowing guest 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. CVE-2016-9379, CVE-2016-9380 (XSA-198) Daniel Richman and Gabor Szarka of the Cambridge University Student-Run Computing Facility discovered that pygrub, the boot loader emulator, fails to quote (or sanity check) its results when reporting them to its caller. A malicious guest administrator can take advantage of this flaw to cause an information leak or denial of service. CVE-2016-9382 (XSA-192) Jan Beulich of SUSE discovered that Xen does not properly handle x86 task switches to VM86 mode. A unprivileged guest process can take advantage of this flaw to crash the guest or, escalate its privileges to that of the guest operating system. CVE-2016-9383 (XSA-195) George Dunlap of Citrix discovered that the Xen x86 64-bit bit test instruction emulation is broken. A malicious guest can take advantage of this flaw to modify arbitrary memory, allowing for arbitrary code execution, denial of service (host crash), or information leaks. CVE-2016-9385 (XSA-193) Andrew Cooper of Citrix discovered that Xen's x86 segment base write emulation lacks canonical address checks. A malicious guest administrator can take advantage of this flaw to crash the host, leading to a denial of service. CVE-2016-9386 (XSA-191) Andrew Cooper of Citrix discovered that x86 null segments are not always treated as unusable. An unprivileged guest user program may be able to elevate its privilege to that of the guest operating system. For the stable distribution (jessie), these problems have been fixed in version 4.4.1-9+deb8u8. We recommend that you upgrade your xen packages. Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/ Mailing list: This email address is being protected from spambots. You need JavaScript enabled to view it.
Debian: DSA-3729-1: xen security update
Multiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems:
