Ubuntu 16.04 LTS / 18.04 LTS : systemd vulnerabilities (USN-3855-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3855-1. 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(121161);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2018-16864", "CVE-2018-16865", "CVE-2018-16866");
  script_xref(name:"USN", value:"3855-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS : systemd vulnerabilities (USN-3855-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"It was discovered that systemd-journald allocated variable-length
buffers for certain message fields on the stack. A local attacker
could potentially exploit this to cause a denial of service, or
execute arbitrary code. (CVE-2018-16864)

It was discovered that systemd-journald allocated variable-length
arrays of objects representing message fields on the stack. A local
attacker could potentially exploit this to cause a denial of service,
or execute arbitrary code. (CVE-2018-16865)

An out-of-bounds read was discovered in systemd-journald. A local
attacker could potentially exploit this to obtain sensitive
information and bypass ASLR protections. (CVE-2018-16866).

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-3855-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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:POC/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:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-16865");

  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:"2019/01/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/01/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/01/14");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:systemd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:systemd-container");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:systemd-coredump");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:systemd-journal-remote");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:systemd-sysv");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:systemd-tests");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:udev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:udev-udeb");
  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:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss-myhostname");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss-mymachines");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss-resolve");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss-systemd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-systemd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libsystemd-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libsystemd0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libudev-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libudev1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libudev1-udeb");
  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) 2019-2023 Canonical, Inc. / NASL script (C) 2019-2023 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 (! ('16.04' >< os_release || '18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 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': '16.04', 'pkgname': 'libnss-myhostname', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libnss-mymachines', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libnss-resolve', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libpam-systemd', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libsystemd-dev', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libsystemd0', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libudev-dev', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libudev1', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'libudev1-udeb', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'systemd', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'systemd-container', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'systemd-coredump', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'systemd-journal-remote', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'systemd-sysv', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'udev', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '16.04', 'pkgname': 'udev-udeb', 'pkgver': '229-4ubuntu21.15'},
    {'osver': '18.04', 'pkgname': 'libnss-myhostname', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libnss-mymachines', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libnss-resolve', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libnss-systemd', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libpam-systemd', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libsystemd-dev', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libsystemd0', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libudev-dev', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libudev1', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'libudev1-udeb', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'systemd', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'systemd-container', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'systemd-coredump', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'systemd-journal-remote', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'systemd-sysv', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'systemd-tests', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'udev', 'pkgver': '237-3ubuntu10.11'},
    {'osver': '18.04', 'pkgname': 'udev-udeb', 'pkgver': '237-3ubuntu10.11'}
];

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_WARNING,
    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, 'libnss-myhostname / libnss-mymachines / libnss-resolve / etc');
}