Ubuntu 14.04 LTS / 16.04 LTS : GnuPG 2 vulnerability (USN-3675-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3675-2. 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(110549);
  script_version("1.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2018-12020");
  script_xref(name:"USN", value:"3675-2");
  script_xref(name:"IAVA", value:"2018-A-0193");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS : GnuPG 2 vulnerability (USN-3675-2)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"USN-3675-1 fixed a vulnerability in GnuPG 2 for Ubuntu 18.04 LTS and
Ubuntu 17.10. This update provides the corresponding update for GnuPG
2 in Ubuntu 16.04 LTS and Ubuntu 14.04 LTS.

Marcus Brinkmann discovered that during decryption or verification,
GnuPG did not properly filter out terminal sequences when reporting
the original filename. An attacker could use this to specially craft a
file that would cause an application parsing GnuPG output to
incorrectly interpret the status of the cryptographic operation
reported by GnuPG.

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-3675-2");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-12020");

  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:"2018/06/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/06/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/06/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnupg2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gpgsm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gpgv-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gpgv2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:scdaemon");
  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:"p-cpe:/a:canonical:ubuntu_linux:dirmngr");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:gnupg-agent");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  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)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04', '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': 'gnupg-agent', 'pkgver': '2.0.22-3ubuntu1.4'},
    {'osver': '14.04', 'pkgname': 'gnupg2', 'pkgver': '2.0.22-3ubuntu1.4'},
    {'osver': '14.04', 'pkgname': 'gpgsm', 'pkgver': '2.0.22-3ubuntu1.4'},
    {'osver': '14.04', 'pkgname': 'gpgv2', 'pkgver': '2.0.22-3ubuntu1.4'},
    {'osver': '14.04', 'pkgname': 'scdaemon', 'pkgver': '2.0.22-3ubuntu1.4'},
    {'osver': '16.04', 'pkgname': 'dirmngr', 'pkgver': '2.1.11-6ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'gnupg-agent', 'pkgver': '2.1.11-6ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'gnupg2', 'pkgver': '2.1.11-6ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'gpgsm', 'pkgver': '2.1.11-6ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'gpgv-udeb', 'pkgver': '2.1.11-6ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'gpgv2', 'pkgver': '2.1.11-6ubuntu2.1'},
    {'osver': '16.04', 'pkgname': 'scdaemon', 'pkgver': '2.1.11-6ubuntu2.1'}
];

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_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, 'dirmngr / gnupg-agent / gnupg2 / gpgsm / gpgv-udeb / gpgv2 / etc');
}