<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd"> <glsa id="201703-07"> <title>Xen: Privilege Escalation</title> <synopsis>A vulnerability in Xen's bundled QEMU version might allow privilege escalation. </synopsis> <product type="ebuild">xen</product> <announced>2017-03-28</announced> <revised count="1">2017-03-28</revised> <bug>609120</bug> <access>local</access> <affected> <package name="app-emulation/xen-tools" auto="yes" arch="*"> <unaffected range="ge">4.7.1-r8</unaffected> <vulnerable range="lt">4.7.1-r8</vulnerable> </package> </affected> <background> <p>Xen is a bare-metal hypervisor.</p> </background> <description> <p>In CIRRUS_BLTMODE_MEMSYSSRC mode the bitblit copy routine cirrus_bitblt_cputovideo fails to check wethehr the specified memory region is safe. </p> </description> <impact type="normal"> <p>A local attacker could potentially execute arbitrary code with privileges of Xen (QEMU) process on the host, gain privileges on the host system, or cause a Denial of Service condition. </p> </impact> <workaround> <p>Running guests in Paravirtualization (PV) mode, or running guests in Hardware-assisted virtualizion (HVM) utilizing stub domains mitigate the issue. </p> <p>Running HVM guests with the device model in a stubdomain will mitigate the issue. </p> <p>Changing the video card emulation to stdvga (stdvga=1, vga=”stdvga”, in the xl domain configuration) will avoid the vulnerability. </p> </workaround> <resolution> <p>All Xen Tools users should upgrade to the latest version:</p> <code> # emerge --sync # emerge --ask --oneshot --verbose ">=app-emulation/xen-tools-4.7.1-r8" </code> </resolution> <references> <uri link="https://nvd.nist.gov/nvd.cfm?cvename=CVE-2017-2620">CVE-2017-2620</uri> </references> <metadata tag="requester" timestamp="2017-02-24T02:24:45Z">BlueKnight</metadata> <metadata tag="submitter" timestamp="2017-03-28T03:15:18Z">whissi</metadata> </glsa>