<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd">
<glsa id="202105-38">
  <title>nginx: Remote code execution</title>
  <synopsis>A vulnerability in nginx could lead to remote code execution.</synopsis>
  <product type="ebuild">nginx</product>
  <announced>2021-05-26</announced>
  <revised count="1">2021-05-26</revised>
  <bug>792087</bug>
  <access>remote</access>
  <affected>
    <package name="www-servers/nginx" auto="yes" arch="*">
      <unaffected range="ge" slot="0">1.20.1</unaffected>
      <unaffected range="ge" slot="mainline">1.21.0</unaffected>
      <vulnerable range="lt">1.21.0</vulnerable>
    </package>
  </affected>
  <background>
    <p>nginx is a robust, small, and high performance HTTP and reverse proxy
      server.
    </p>
  </background>
  <description>
    <p>It was discovered that nginx did not properly handle DNS responses when
      “resolver” directive is used.
    </p>
  </description>
  <impact type="high">
    <p>A remote attacker, able to provide DNS responses to a nginx instance,
      could cause the execution of arbitrary code with the privileges of the
      process or a Denial of Service condition.
    </p>
  </impact>
  <workaround>
    <p>There is no known workaround at this time.</p>
  </workaround>
  <resolution>
    <p>All nginx users should upgrade to the latest version:</p>
    
    <code>
      # emerge --sync
      # emerge --ask --oneshot --verbose "&gt;=www-servers/nginx-1.20.1"
    </code>
    
    <p>All nginx mainline users should upgrade to the latest version:</p>
    
    <code>
      # emerge --sync
      # emerge --ask --oneshot --verbose
      "&gt;=www-servers/nginx-1.21.0:mainline"
    </code>
    
  </resolution>
  <references>
    <uri link="https://nvd.nist.gov/vuln/detail/CVE-2021-23017">CVE-2021-23017</uri>
  </references>
  <metadata tag="requester" timestamp="2021-05-26T17:05:23Z">whissi</metadata>
  <metadata tag="submitter" timestamp="2021-05-26T17:40:33Z">whissi</metadata>
</glsa>
