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("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  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 host has packages installed that are affected by multiple vulnerabilities as
referenced in the USN-5008-1 advisory.

    Thomas Kremer discovered that Avahi incorrectly handled termination signals on the Unix socket. A local
    attacker could possibly use this issue to cause Avahi to hang, resulting in a denial of service. This
    issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 20.10. (CVE-2021-3468)

    It was discovered that Avahi incorrectly handled certain hostnames. A local attacker could possibly use
    this issue to cause Avahi to crash, resulting in a denial of service. This issue only affected Ubuntu
    20.10 and Ubuntu 21.04. (CVE-2021-3502)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

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://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_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2021-2024 Canonical, Inc. / NASL script (C) 2021-2024 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 var 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)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_NOTE,
    extra      : extra
  );
  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');
}