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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2016.2890 xen security update 8 December 2016 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: xen Publisher: Debian Operating System: Debian GNU/Linux 8 Impact/Access: Execute Arbitrary Code/Commands -- Existing Account Increased Privileges -- Existing Account Denial of Service -- Existing Account Access Confidential Data -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2016-9386 CVE-2016-9385 CVE-2016-9383 CVE-2016-9382 CVE-2016-9380 CVE-2016-9379 CVE-2016-7777 Reference: ESB-2016.2876 ESB-2016.2814 ESB-2016.2809 Original Bulletin: http://www.debian.org/security/2016/dsa-3729 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 - - ------------------------------------------------------------------------- Debian Security Advisory DSA-3729-1 security@debian.org 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: debian-security-announce@lists.debian.org - -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEERkRAmAjBceBVMd3uBUy48xNDz0QFAlhIbjZfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldDQ2 NDQ0MDk4MDhDMTcxRTA1NTMxRERFRTA1NENCOEYzMTM0M0NGNDQACgkQBUy48xND z0SD6Q//RmK2M5EWJ2/yNi4r5q6JKNZCwdx8/Nu/dUhjKkAAwITJVE+CNdkAVQLU JMrGgacBnddwAxn1B/u7Ms3dMsHomzST+s0huwudbQ5QZQyS2bY5h2BjAt2MsKwJ t5bKpX9tmBrOM4101jAnnnTUB8S+N4EZLb/zFvhxNpWT6VlIZrN9PEPzd1cMBdQv 2Bt4RA7PwJnq5bWffqbMt3jz5OxO9Y9r9pw/Jghk1XfvDH8wZOonD78g6H9NfEL0 /QcW5ZG2ZafNYXRz8eaV6+9lClbssCB8pGDG7r5N/n5OATw/DkcZtMkrO1uJWWtl JS2l1E6nzsvWgZFEjuLmTAXjjlIVioHinqKiFi96KZ3C+DyQXNtoEp6PWcvsGzRi Y1bnq4NV3nXXrfPUqCKQUNoy3pTcmEBFgvEhhtMgi3Uz2aDqD9i2uiVJeXCW4OFc Eb3bXLRsW5JVhJQs/ENg0Ipq3jYhM43ZfCY0zniNepcnJuWHfckFS+vZnlDSVNR9 sIJXoQbPHlCiCK/Z7qnzc3YCTM3LnEAOWH3WbQXQt6K9Nv8mH8/LgWjw+5mve1FW rLouJ4+bNBwNGXFpPEmjrBMpvcpQTPUS/XQqm09VCQhQj+qGKVpzePovsyhu6Pnj lvrZV+KJnoTGIIXPe5Z3yA++LndLcSQuPYP6gon4Jx60IZWLxGQ= =EyoZ - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBWEj8fYx+lLeg9Ub1AQi07w//Qj97PqQWN2TYH1PTkvfJeBCl6s0+lqKB XfvVULxYuHaq/o1GTEJ4fDSwsWbsQsjmMTkm5V1UY2oDAL2tJecUWLNwWKdKDoCc 63FnqTzQxZAVCWV6CWCeIFSUHk9IMJJ2E5t9e9a+XGCvKU8gv21U6cFMNyQZLJ8E 86BxC7cs1sRus2S/70/1hxccRy9cdDnnCJBQsqe5uE1Ncw13dyrc0AWPdZokqNYJ BSkb0ZB9AXOwzoQgeB8wku8kOz9jopWyeV8d47p4+8PoeZzzlpXz2+GLQYpKiC+2 A/mpBt9N7pPwK1liUUSbnV2BunpGNT/YZ3MbDJqLqBVH49BeSd7aCCUMaoBWNEcw iXLnWJBhbUjARgkhZ6nR9kqRFT+hZ/PJShDC27xE2+9DrM0L1rZW2LrEWKWBoTYb Dnq/oomyOHjzVsNLTE9C0sptIHbVUBjqpYyx4LcCu9giXk4MqzXh17NE3e3HhPrx dRIblLiklWMZ4RFq5wtCdvtdmqUafeo1+/D7WTYcoPkvvoEVg6X6bHfjGGxbauB7 OD19YmMh9OY7wi5qufMcN7MM4VAJLCW0vVW4X3HJyVmk7XcAQqehVDAGIzpOgtqd tnIL7LdQ2UY55XKF8tSv4jYoZnU+3eAwTyZ9WOsmI7GS5DiZ+cLKHHq9SyXCj36R Cagju5qFJjI= =x0Gv -----END PGP SIGNATURE-----