<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd"> <glsa id="201612-02"> <title>DavFS2: Local privilege escalation</title> <synopsis>A vulnerability in DavFS2 allows local users to gain root privileges. </synopsis> <product type="ebuild">davfs2</product> <announced>2016-12-02</announced> <revised count="1">2016-12-02</revised> <bug>485232</bug> <access>local</access> <affected> <package name="net-fs/davfs2" auto="yes" arch="*"> <unaffected range="ge">1.5.2</unaffected> <vulnerable range="lt">1.5.2</vulnerable> </package> </affected> <background> <p>DavFS2 is a file system driver that allows you to mount a WebDAV server as a local disk drive. </p> </background> <description> <p>DavFS2 installs “/usr/sbin/mount.davfs” as setuid root. This utility uses “system()” to call “/sbin/modprobe”. </p> <p>While the call to “modprobe” itself cannot be manipulated, a local authenticated user can set the “MODPROBE_OPTIONS” environment variable to pass a user controlled path, allowing the loading of an arbitrary kernel module. </p> </description> <impact type="normal"> <p>A local user could gain root privileges.</p> </impact> <workaround> <p>The system administrator should ensure that all modules the “mount.davfs” utility tries to load are loaded upon system boot before any local user can call the utility. </p> <p>An additional defense measure can be implemented by enabling the Linux kernel module signing feature. This assists in the prevention of arbitrary modules being loaded. </p> </workaround> <resolution> <p>All DavFS2 users should upgrade to the latest version:</p> <code> # emerge --sync # emerge --ask --oneshot --verbose ">=net-fs/davfs2-1.5.2" </code> </resolution> <references> <uri link="https://nvd.nist.gov/nvd.cfm?cvename=CVE-2013-4362">CVE-2013-4362</uri> </references> <metadata tag="requester" timestamp="2015-12-07T21:54:18Z"> BlueKnight </metadata> <metadata tag="submitter" timestamp="2016-12-02T13:32:55Z">whissi</metadata> </glsa>