<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd">
<glsa id="202004-08">
  <title>libssh: Denial of service</title>
  <synopsis>A vulnerability in libssh could allow a remote attacker to cause a
    Denial of Service condition.
  </synopsis>
  <product type="ebuild">libssh</product>
  <announced>2020-04-10</announced>
  <revised count="1">2020-04-10</revised>
  <bug>716788</bug>
  <access>remote</access>
  <affected>
    <package name="net-libs/libssh" auto="yes" arch="*">
      <unaffected range="ge">0.9.4</unaffected>
      <vulnerable range="lt">0.9.4</vulnerable>
    </package>
  </affected>
  <background>
    <p>libssh is a multiplatform C library implementing the SSHv2 protocol on
      client and server side.
    </p>
  </background>
  <description>
    <p>It was discovered that libssh could crash when AES-CTR ciphers are used.</p>
  </description>
  <impact type="low">
    <p>A remote attacker running a malicious client or server could possibly
      crash the counterpart implemented with libssh and cause a Denial of
      Service condition.
    </p>
  </impact>
  <workaround>
    <p>Disable AES-CTR ciphers. If you implement a server using libssh it is
      recommended to use a prefork model so each session runs in an own
      process.
    </p>
  </workaround>
  <resolution>
    <p>All libssh users should upgrade to the latest version:</p>
    
    <code>
      # emerge --sync
      # emerge --ask --oneshot --verbose "&gt;=net-libs/libssh-0.9.4"
    </code>
    
  </resolution>
  <references>
    <uri link="https://nvd.nist.gov/vuln/detail/CVE-2020-1730">CVE-2020-1730</uri>
  </references>
  <metadata tag="requester" timestamp="2020-04-10T21:38:04Z">whissi</metadata>
  <metadata tag="submitter" timestamp="2020-04-10T21:45:49Z">whissi</metadata>
</glsa>
