Debian DLA-3047-1 : avahi - LTS security update

#
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory dla-3047. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

include('compat.inc');

if (description)
{
  script_id(161940);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/06/08");

  script_cve_id("CVE-2021-3468", "CVE-2021-26720");

  script_name(english:"Debian DLA-3047-1 : avahi - LTS security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The remote Debian 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the
dla-3047 advisory.

  - avahi-daemon-check-dns.sh in the Debian avahi package through 0.8-4 is executed as root via
    /etc/network/if-up.d/avahi-daemon, and allows a local attacker to cause a denial of service or create
    arbitrary empty files via a symlink attack on files under /run/avahi-daemon. NOTE: this only affects the
    packaging for Debian GNU/Linux (used indirectly by SUSE), not the upstream Avahi product. (CVE-2021-26720)

  - A flaw was found in avahi in versions 0.6 up to 0.8. The event used to signal the termination of the
    client connection on the avahi Unix socket is not correctly handled in the client_work function, allowing
    a local attacker to trigger an infinite loop. The highest threat from this vulnerability is to the
    availability of the avahi service, which becomes unresponsive after this flaw is triggered.
    (CVE-2021-3468)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=984938");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/source-package/avahi");
  script_set_attribute(attribute:"see_also", value:"https://www.debian.org/lts/security/2022/dla-3047");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-26720");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2021-3468");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/stretch/avahi");
  script_set_attribute(attribute:"solution", value:
"Upgrade the avahi packages.

For Debian 9 stretch, these problems have been fixed in version 0.6.32-2+deb9u1.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-26720");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/02/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/06/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/06/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:avahi-autoipd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:avahi-daemon");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:avahi-discover");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:avahi-dnsconfd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:avahi-ui-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:avahi-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-client-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-client3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-common-data");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-common-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-common3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-compat-libdnssd-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-compat-libdnssd1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-core-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-core7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-glib-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-glib1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-gobject-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-gobject0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-qt4-1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-qt4-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-ui-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-ui-gtk3-0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-ui-gtk3-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libavahi-ui0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:python-avahi");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Debian Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);

var release = get_kb_item('Host/Debian/release');
if ( isnull(release) ) audit(AUDIT_OS_NOT, 'Debian');
var release = chomp(release);
if (! preg(pattern:"^(9)\.[0-9]+", string:release)) audit(AUDIT_OS_NOT, 'Debian 9.0', 'Debian ' + release);
var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Debian', cpu);

var pkgs = [
    {'release': '9.0', 'prefix': 'avahi-autoipd', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'avahi-daemon', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'avahi-discover', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'avahi-dnsconfd', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'avahi-ui-utils', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'avahi-utils', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-client-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-client3', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-common-data', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-common-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-common3', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-compat-libdnssd-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-compat-libdnssd1', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-core-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-core7', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-glib-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-glib1', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-gobject-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-gobject0', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-qt4-1', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-qt4-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-ui-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-ui-gtk3-0', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-ui-gtk3-dev', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'libavahi-ui0', 'reference': '0.6.32-2+deb9u1'},
    {'release': '9.0', 'prefix': 'python-avahi', 'reference': '0.6.32-2+deb9u1'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var release = NULL;
  var prefix = NULL;
  var reference = NULL;
  if (!empty_or_null(package_array['release'])) release = package_array['release'];
  if (!empty_or_null(package_array['prefix'])) prefix = package_array['prefix'];
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (release && prefix && reference) {
    if (deb_check(release:release, prefix:prefix, reference:reference)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : deb_report_get()
  );
  exit(0);
}
else
{
  var tested = deb_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'avahi-autoipd / avahi-daemon / avahi-discover / avahi-dnsconfd / etc');
}