metadata/glsa/glsa-201601-01.xml


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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd">
<glsa id="201601-01">
  <title>OpenSSH: Multiple vulnerabilities</title>
  <synopsis>Multiple vulnerabilities have been found in OpenSSH, allowing
    attackers to leak client memory to a server, including private keys.
  </synopsis>
  <product type="ebuild">openssh</product>
  <announced>2016-01-16</announced>
  <revised count="1">2016-01-16</revised>
  <bug>571892</bug>
  <access>remote</access>
  <affected>
    <package name="net-misc/openssh" auto="yes" arch="*">
      <unaffected range="ge">7.1_p2</unaffected>
      <vulnerable range="lt">7.1_p2</vulnerable>
    </package>
  </affected>
  <background>
    <p>OpenSSH is a complete SSH protocol implementation that includes SFTP
      client and server support.
    </p>
  </background>
  <description>
    <p>Qualys have reported two issues in the “roaming” code included in
      the OpenSSH client, which provides undocumented, experimental support for
      resuming SSH connections. An OpenSSH client could be tricked into leaking
      parts of its memory to a malicious server. Furthermore, a buffer overflow
      can be exploited by a malicious server, but its exploitation requires
      non-default options and is mitigated due to another bug.
    </p>
  </description>
  <impact type="normal">
    <p>A remote attacker could entice a user to connect to a specially crafted
      OpenSSH server, possibly resulting in the disclosure of the user’s
      private keys. Users with private keys that are not protected by a
      passphrase are advised to generate new keys if they have connected to an
      SSH server they don’t fully trust.
    </p>
    
    <p>Note that no special configuration is required to be vulnerable as the
      roaming feature is enabled by default on the client.
    </p>
  </impact>
  <workaround>
    <p>The issues can be worked around by disabling the roaming code. To do so,
      add “UseRoaming no” to the SSH client configuration, or specify “-o
      ‘UseRoaming no’” on the command line.
    </p>
  </workaround>
  <resolution>
    <p>All OpenSSH users should upgrade to the latest version:</p>
    
    <code>
      # emerge --sync
      # emerge --ask --oneshot --verbose "&gt;=net-misc/openssh-7.1_p2"
    </code>
    
  </resolution>
  <references>
    <uri link="https://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0777">CVE-2016-0777</uri>
    <uri link="https://nvd.nist.gov/nvd.cfm?cvename=CVE-2016-0778">CVE-2016-0778</uri>
  </references>
  <metadata tag="requester" timestamp="2016-01-14T09:15:59Z">a3li</metadata>
  <metadata tag="submitter" timestamp="2016-01-16T18:56:11Z">a3li</metadata>
</glsa>