Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : NTP vulnerabilities (USN-3707-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3707-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include('compat.inc');

if (description)
{
  script_id(110974);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/21");

  script_cve_id(
    "CVE-2018-7182",
    "CVE-2018-7183",
    "CVE-2018-7184",
    "CVE-2018-7185"
  );
  script_xref(name:"USN", value:"3707-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : NTP vulnerabilities (USN-3707-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"Yihan Lian discovered that NTP incorrectly handled certain malformed
mode 6 packets. A remote attacker could possibly use this issue to
cause ntpd to crash, resulting in a denial of service. This issue only
affected Ubuntu 17.10 and Ubuntu 18.04 LTS. (CVE-2018-7182)

Michael Macnair discovered that NTP incorrectly handled certain
responses. A remote attacker could possibly use this issue to execute
arbitrary code. (CVE-2018-7183)

Miroslav Lichvar discovered that NTP incorrectly handled certain
zero-origin timestamps. A remote attacker could possibly use this
issue to cause a denial of service. This issue only affected Ubuntu
17.10 and Ubuntu 18.04 LTS. (CVE-2018-7184)

Miroslav Lichvar discovered that NTP incorrectly handled certain
zero-origin timestamps. A remote attacker could possibly use this
issue to cause a denial of service. (CVE-2018-7185).

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-3707-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected ntp, ntpdate and / or sntp packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-7183");

  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:"2018/03/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/07/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/07/10");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ntp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ntpdate");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:sntp");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  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) 2018-2023 Canonical, Inc. / NASL script (C) 2018-2023 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 (! ('14.04' >< os_release || '16.04' >< os_release || '18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04', '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': '14.04', 'pkgname': 'ntp', 'pkgver': '1:4.2.6.p5+dfsg-3ubuntu2.14.04.13'},
    {'osver': '14.04', 'pkgname': 'ntpdate', 'pkgver': '1:4.2.6.p5+dfsg-3ubuntu2.14.04.13'},
    {'osver': '16.04', 'pkgname': 'ntp', 'pkgver': '1:4.2.8p4+dfsg-3ubuntu5.9'},
    {'osver': '16.04', 'pkgname': 'ntpdate', 'pkgver': '1:4.2.8p4+dfsg-3ubuntu5.9'},
    {'osver': '18.04', 'pkgname': 'ntp', 'pkgver': '1:4.2.8p10+dfsg-5ubuntu7.1'},
    {'osver': '18.04', 'pkgname': 'ntpdate', 'pkgver': '1:4.2.8p10+dfsg-5ubuntu7.1'},
    {'osver': '18.04', 'pkgname': 'sntp', 'pkgver': '1:4.2.8p10+dfsg-5ubuntu7.1'}
];

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_HOLE,
    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, 'ntp / ntpdate / sntp');
}