Ubuntu 18.04 LTS / 20.04 LTS : Avahi vulnerabilities (USN-5008-1)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5008-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(151452);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/16");

  script_cve_id("CVE-2021-3468", "CVE-2021-3502");
  script_xref(name:"USN", value:"5008-1");

  script_name(english:"Ubuntu 18.04 LTS / 20.04 LTS : Avahi vulnerabilities (USN-5008-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 18.04 LTS / 20.04 LTS / 20.10 / 21.04 host has packages installed that are affected by multiple
vulnerabilities as referenced in the USN-5008-1 advisory.

  - 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)

  - A flaw was found in avahi 0.8-5. A reachable assertion is present in avahi_s_host_name_resolver_start
    function allowing a local attacker to crash the avahi service by requesting hostname resolutions through
    the avahi socket or dbus methods for invalid hostnames. The highest threat from this vulnerability is to
    the service availability. (CVE-2021-3502)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-5008-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-3502");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/05/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/07/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/07/08");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:avahi-autoipd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:avahi-daemon");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:avahi-discover");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:avahi-dnsconfd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:avahi-ui-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:avahi-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gir1.2-avahi-0.6");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-client-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-client3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-common-data");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-common-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-common3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-common3-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-compat-libdnssd-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-compat-libdnssd1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-core-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-core7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-core7-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-glib-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-glib1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-gobject-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-gobject0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-ui-gtk3-0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libavahi-ui-gtk3-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-avahi");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2021-2023 Canonical, Inc. / NASL script (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/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);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 18.04 / 20.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '18.04', 'pkgname': 'avahi-autoipd', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'avahi-daemon', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'avahi-discover', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'avahi-dnsconfd', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'avahi-ui-utils', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'avahi-utils', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'gir1.2-avahi-0.6', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-client-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-client3', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-common-data', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-common-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-common3', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-common3-udeb', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-compat-libdnssd-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-compat-libdnssd1', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-core-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-core7', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-core7-udeb', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-glib-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-glib1', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-gobject-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-gobject0', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-ui-gtk3-0', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'libavahi-ui-gtk3-dev', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '18.04', 'pkgname': 'python-avahi', 'pkgver': '0.7-3.1ubuntu1.3'},
    {'osver': '20.04', 'pkgname': 'avahi-autoipd', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'avahi-daemon', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'avahi-discover', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'avahi-dnsconfd', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'avahi-ui-utils', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'avahi-utils', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'gir1.2-avahi-0.6', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-client-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-client3', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-common-data', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-common-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-common3', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-common3-udeb', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-compat-libdnssd-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-compat-libdnssd1', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-core-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-core7', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-core7-udeb', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-glib-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-glib1', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-gobject-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-gobject0', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-ui-gtk3-0', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'libavahi-ui-gtk3-dev', 'pkgver': '0.7-4ubuntu7.1'},
    {'osver': '20.04', 'pkgname': 'python-avahi', 'pkgver': '0.7-4ubuntu7.1'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_NOTE,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_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');
}