source: postlfs/security/vulnerabilities.xml@ 5374aca

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<sect1 id="vulnerabilities" xreflabel="vulnerabilities">
  <?dbhtml filename="vulnerabilities.html"?>


  <title>Vulnerabilities</title>

  <!-- section g : 'Others' in longindex.html -->
  <indexterm zone="vulnerabilities">
    <primary sortas="g-vulnerabilities">vulnerability links</primary>
  </indexterm>

  <sect2 role="package">
    <title>About vulnerabilities</title>

    <para>
      All software has bugs. Sometimes, a bug can be exploited, for example to
      allow users to gain enhanced privileges (perhaps gaining a root shell,
      or simply accessing or deleting other user&apos;s files), or to allow a
      remote site to crash an application (denial of service), or for theft of
      data. These bugs are labelled as vulnerabilities.
    </para>

    <para>
      The main place where vulnerabilities get logged is
      <ulink url="https://cve.mitre.org">cve.mitre.org</ulink>. Unfortunately,
      many vulnerability numbers (CVE-yyyy-nnnn) are initially only labelled
      as "reserved" when distributions start issuing fixes.  Also, some
      vulnerabilities apply to particular combinations of
      <command>configure</command> options, or only apply to old versions of
      packages which have long since been updated in BLFS.
    </para>

    <para>
      BLFS differs from distributions&mdash;there is no BLFS security team, and
      the editors only become aware of vulnerabilities after they are public
      knowledge. Sometimes, a package with a vulnerability will not be updated
      in the book for a long time.  Issues can be logged in the Trac system,
      which might speed up resolution.
    </para>

    <para>
      The normal way for BLFS to fix a vulnerability is, ideally, to update
      the book to a new fixed release of the package.  Sometimes that happens
      even before the vulnerability is public knowledge, so there is no
      guarantee that it will be shown as a vulnerability fix in the Changelog.
      Alternatively, a <command>sed</command> command, or a patch taken from
      a distribution, may be appropriate.
    </para>

    <para>
      The bottom line is that you are responsible for your own security, and
      for assessing the potential impact of any problems.
    </para>

    <para>
      The editors now issue Security Advisories for packages in BLFS (and LFS),
      which can be found at <ulink
      url="https://www.linuxfromscratch.org/blfs/advisories/">BLFS Security
      Advisories</ulink>, and grade the severity according to what upstream
      reports, or to what is shown at <ulink
      url="https://nvd.nist.gov/">nvd.nist.gov</ulink> if that has details.
    </para>

    <para>
      To keep track of what is being discovered, you may wish to follow the
      security announcements of one or more distributions. For example, Debian
      has <ulink url="https://www.debian.org/security">Debian security</ulink>.
      Fedora's links on security are at <ulink
        url="https://fedoraproject.org/wiki/category:Security">the Fedora wiki</ulink>.
      Details of Gentoo linux security announcements are discussed at
      <ulink url="https://security.gentoo.org">Gentoo security</ulink>.
      Finally, the Slackware archives of security announcements are at
      <ulink url="https://slackware.com/security">Slackware security</ulink>.
    </para>

    <para>
      The most general English source is perhaps
      <ulink url="https://seclists.org/fulldisclosure">the Full Disclosure
      Mailing List</ulink>, but please read the comment on that page. If you
      use other languages you may prefer other sites such as <ulink
        url="https://www.heise.de/security">heise.de</ulink> (German) or <ulink
        url="https://www.cert.hr">cert.hr</ulink> (Croatian). These are not
      linux-specific. There is also a daily update at lwn.net for subscribers
      (free access to the data after 2 weeks, but their vulnerabilities
      database at <ulink
        url="https://lwn.net/Alerts/">lwn.net/Alerts</ulink>
      is unrestricted).
    </para>

    <para>
      For some packages, subscribing to their &apos;announce&apos; lists
      will provide prompt news of newer versions.
    </para>

  </sect2>

</sect1>