Ubuntu 16.04 LTS / 18.04 LTS : Snapcraft vulnerability (USN-4661-1)

##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4661-1. 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(143476);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/21");

  script_cve_id("CVE-2020-27348");
  script_xref(name:"USN", value:"4661-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS : Snapcraft vulnerability (USN-4661-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by a vulnerability as referenced
in the USN-4661-1 advisory.

  - In some conditions, a snap package built by snapcraft includes the current directory in LD_LIBRARY_PATH,
    allowing a malicious snap to gain code execution within the context of another snap if both plug the home
    interface or similar. This issue affects snapcraft versions prior to 4.4.4, prior to 2.43.1+16.04.1, and
    prior to 2.43.1+18.04.1. (CVE-2020-27348)

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-4661-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected snapcraft, snapcraft-examples and / or snapcraft-parser packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/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:R/S:U/C:H/I:H/A:L");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-27348");

  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:"2020/12/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/12/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/12/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:snapcraft");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:snapcraft-examples");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:snapcraft-parser");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2020-2023 Canonical, Inc. / NASL script (C) 2020-2023 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': 'snapcraft', 'pkgver': '2.43.1+16.04.1'},
    {'osver': '16.04', 'pkgname': 'snapcraft-examples', 'pkgver': '2.43.1+16.04.1'},
    {'osver': '16.04', 'pkgname': 'snapcraft-parser', 'pkgver': '2.43.1+16.04.1'},
    {'osver': '18.04', 'pkgname': 'snapcraft', 'pkgver': '2.43.1+18.04.1'},
    {'osver': '18.04', 'pkgname': 'snapcraft-examples', 'pkgver': '2.43.1+18.04.1'},
    {'osver': '18.04', 'pkgname': 'snapcraft-parser', 'pkgver': '2.43.1+18.04.1'}
];

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, 'snapcraft / snapcraft-examples / snapcraft-parser');
}