Ubuntu 16.04 ESM / 18.04 LTS / 20.04 LTS / 22.04 LTS : Ghostscript vulnerability (USN-6017-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6017-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(174272);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/16");

  script_cve_id("CVE-2023-28879");
  script_xref(name:"USN", value:"6017-1");
  script_xref(name:"IAVB", value:"2023-B-0023-S");

  script_name(english:"Ubuntu 16.04 ESM / 18.04 LTS / 20.04 LTS / 22.04 LTS : Ghostscript vulnerability (USN-6017-1)");

  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 ESM / 18.04 LTS / 20.04 LTS / 22.04 LTS / 22.10 host has packages installed that are affected by
a vulnerability as referenced in the USN-6017-1 advisory.

  - In Artifex Ghostscript through 10.01.0, there is a buffer overflow leading to potential corruption of data
    internal to the PostScript interpreter, in base/sbcp.c. This affects BCPEncode, BCPDecode, TBCPEncode, and
    TBCPDecode. If the write buffer is filled to one byte less than full, and one then tries to write an
    escaped character, two bytes are written. (CVE-2023-28879)

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-6017-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  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: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-2023-28879");

  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:"2023/03/31");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/04/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/04/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:esm");
  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:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ghostscript");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:ghostscript-x");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgs-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgs9");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libgs9-common");
  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) 2023 Canonical, Inc. / NASL script (C) 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 || '20.04' >< os_release || '22.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04', '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': 'ghostscript', 'pkgver': '9.26~dfsg+0-0ubuntu0.16.04.14+esm5'},
    {'osver': '16.04', 'pkgname': 'ghostscript-x', 'pkgver': '9.26~dfsg+0-0ubuntu0.16.04.14+esm5'},
    {'osver': '16.04', 'pkgname': 'libgs-dev', 'pkgver': '9.26~dfsg+0-0ubuntu0.16.04.14+esm5'},
    {'osver': '16.04', 'pkgname': 'libgs9', 'pkgver': '9.26~dfsg+0-0ubuntu0.16.04.14+esm5'},
    {'osver': '16.04', 'pkgname': 'libgs9-common', 'pkgver': '9.26~dfsg+0-0ubuntu0.16.04.14+esm5'},
    {'osver': '18.04', 'pkgname': 'ghostscript', 'pkgver': '9.26~dfsg+0-0ubuntu0.18.04.18'},
    {'osver': '18.04', 'pkgname': 'ghostscript-x', 'pkgver': '9.26~dfsg+0-0ubuntu0.18.04.18'},
    {'osver': '18.04', 'pkgname': 'libgs-dev', 'pkgver': '9.26~dfsg+0-0ubuntu0.18.04.18'},
    {'osver': '18.04', 'pkgname': 'libgs9', 'pkgver': '9.26~dfsg+0-0ubuntu0.18.04.18'},
    {'osver': '18.04', 'pkgname': 'libgs9-common', 'pkgver': '9.26~dfsg+0-0ubuntu0.18.04.18'},
    {'osver': '20.04', 'pkgname': 'ghostscript', 'pkgver': '9.50~dfsg-5ubuntu4.7'},
    {'osver': '20.04', 'pkgname': 'ghostscript-x', 'pkgver': '9.50~dfsg-5ubuntu4.7'},
    {'osver': '20.04', 'pkgname': 'libgs-dev', 'pkgver': '9.50~dfsg-5ubuntu4.7'},
    {'osver': '20.04', 'pkgname': 'libgs9', 'pkgver': '9.50~dfsg-5ubuntu4.7'},
    {'osver': '20.04', 'pkgname': 'libgs9-common', 'pkgver': '9.50~dfsg-5ubuntu4.7'},
    {'osver': '22.04', 'pkgname': 'ghostscript', 'pkgver': '9.55.0~dfsg1-0ubuntu5.2'},
    {'osver': '22.04', 'pkgname': 'ghostscript-x', 'pkgver': '9.55.0~dfsg1-0ubuntu5.2'},
    {'osver': '22.04', 'pkgname': 'libgs-dev', 'pkgver': '9.55.0~dfsg1-0ubuntu5.2'},
    {'osver': '22.04', 'pkgname': 'libgs9', 'pkgver': '9.55.0~dfsg1-0ubuntu5.2'},
    {'osver': '22.04', 'pkgname': 'libgs9-common', 'pkgver': '9.55.0~dfsg1-0ubuntu5.2'}
];

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, 'ghostscript / ghostscript-x / libgs-dev / libgs9 / libgs9-common');
}