Debian Security Advisory

DSA-3663-1 xen -- security update

Date Reported:
09 Sep 2016
Affected Packages:
Security database references:
In Mitre's CVE dictionary: CVE-2016-7092, CVE-2016-7094, CVE-2016-7154.
More information:

Multiple vulnerabilities have been discovered in the Xen hypervisor. The Common Vulnerabilities and Exposures project identifies the following problems:

  • CVE-2016-7092 (XSA-185)

    Jeremie Boutoille of Quarkslab and Shangcong Luan of Alibaba discovered a flaw in the handling of L3 pagetable entries, allowing a malicious 32-bit PV guest administrator can escalate their privilege to that of the host.

  • CVE-2016-7094 (XSA-187)

    x86 HVM guests running with shadow paging use a subset of the x86 emulator to handle the guest writing to its own pagetables. Andrew Cooper of Citrix discovered that there are situations a guest can provoke which result in exceeding the space allocated for internal state. A malicious HVM guest administrator can cause Xen to fail a bug check, causing a denial of service to the host.

  • CVE-2016-7154 (XSA-188)

    Mikhail Gorobets of Advanced Threat Research, Intel Security discovered a use after free flaw in the FIFO event channel code. A malicious guest administrator can crash the host, leading to a denial of service. Arbitrary code execution (and therefore privilege escalation), and information leaks, cannot be excluded.

For the stable distribution (jessie), these problems have been fixed in version 4.4.1-9+deb8u7.

We recommend that you upgrade your xen packages.