gentoo-overlay/metadata/glsa/glsa-200509-15.xml

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd">
<glsa id="200509-15">
  <title>util-linux: umount command validation error</title>
  <synopsis>
    A command validation error in umount can lead to an escalation of
    privileges.
  </synopsis>
  <product type="ebuild">util-linux</product>
  <announced>2005-09-20</announced>
  <revised count="01">2005-09-20</revised>
  <bug>105805</bug>
  <access>local</access>
  <affected>
    <package name="sys-apps/util-linux" auto="yes" arch="*">
      <unaffected range="ge">2.12q-r3</unaffected>
      <vulnerable range="lt">2.12q-r3</vulnerable>
    </package>
  </affected>
  <background>
    <p>
    util-linux is a suite of useful Linux programs including umount, a
    program used to unmount filesystems.
    </p>
  </background>
  <description>
    <p>
    When a regular user mounts a filesystem, they are subject to
    restrictions in the /etc/fstab configuration file. David Watson
    discovered that when unmounting a filesystem with the '-r' option, the
    read-only bit is set, while other bits, such as nosuid or nodev, are
    not set, even if they were previously.
    </p>
  </description>
  <impact type="high">
    <p>
    An unprivileged user facing nosuid or nodev restrictions can
    umount -r a filesystem clearing those bits, allowing applications to be
    executed suid, or have device nodes interpreted. In the case where the
    user can freely modify the contents of the filesystem, privilege
    escalation may occur as a custom program may execute with suid
    permissions.
    </p>
  </impact>
  <workaround>
    <p>
    Two workarounds exist, first, the suid bit can be removed from the
    umount utility, or users can be restricted from mounting and unmounting
    filesystems in /etc/fstab.
    </p>
  </workaround>
  <resolution>
    <p>
    All util-linux users should upgrade to the latest version:
    </p>
    <code>
    # emerge --sync
    # emerge --ask --oneshot --verbose "&gt;=sys-apps/util-linux-2.12q-r3"</code>
  </resolution>
  <references>
    <uri link="https://www.cve.mitre.org/cgi-bin/cvename.cgi?name=2005-2876">CAN-2005-2876</uri>
  </references>
  <metadata tag="requester" timestamp="2005-09-17T16:18:46Z">
    koon
  </metadata>
  <metadata tag="submitter" timestamp="2005-09-19T16:52:19Z">
    r2d2
  </metadata>
  <metadata tag="bugReady" timestamp="2005-09-20T14:09:16Z">
    koon
  </metadata>
</glsa>