Fortinet FortiOS 5.x < 5.0.3 Security Bypass

#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(73526);
  script_version("1.3");
  script_cvs_date("Date: 2018/07/11 17:09:25");

  script_cve_id("CVE-2013-4604");
  script_bugtraq_id(60571);

  script_name(english:"Fortinet FortiOS 5.x < 5.0.3 Security Bypass");
  script_summary(english:"Checks version of FortiOS");

  script_set_attribute(attribute:"synopsis", value:"The remote host is affected by a security bypass vulnerability.");
  script_set_attribute(attribute:"description", value:
"The remote host is running FortiOS 5.x prior to 5.0.3. It is,
therefore, affected by a security bypass vulnerability due to a
failure to properly manage the Guest user permission. An attacker
could potentially exploit this vulnerability to view, change, or
delete records of users from another group.");
  script_set_attribute(attribute:"see_also", value:"http://www.fortiguard.com/advisory/FGA-2013-20");
  script_set_attribute(attribute:"solution", value:"Upgrade to Fortinet FortiOS 5.0.3 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2013/06/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2013/06/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/04/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:fortinet:fortios");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Firewalls");

  script_copyright(english:"This script is Copyright (C) 2014-2018 Tenable Network Security, Inc.");

  script_dependencies("fortinet_version.nbin");
  script_require_keys("Host/Fortigate/model", "Host/Fortigate/version", "Host/Fortigate/build");

  exit(0);
}

include("audit.inc");
include("global_settings.inc");
include("misc_func.inc");

app_name = "FortiOS";
model = get_kb_item_or_exit("Host/Fortigate/model");
version = get_kb_item_or_exit("Host/Fortigate/version");
build = get_kb_item_or_exit("Host/Fortigate/build");
vuln = FALSE;

# Make sure device is FortiGate or FortiWiFi.
if (!preg(string:model, pattern:"forti(gate|wifi)", icase:TRUE)) audit(AUDIT_OS_NOT, app_name);

# Only 5.x is affected.
if (version =~ "^5\.")
{
  fix = "5.0.3";
  fix_build = 208;
}
else audit(AUDIT_INST_VER_NOT_VULN, app_name, version);

# If build number is available, this is the safest comparison.
# Otherwise compare version numbers.
if (build !~ "Unknown")
{
  if (int(build) < fix_build) vuln = TRUE;
}
else if (ver_compare(ver:version, fix:fix, strict:FALSE) == -1) vuln = TRUE;

if (vuln)
{
  port = 0;
  if (report_verbosity > 0)
  {
    report =
      '\n  Model             : ' + model +
      '\n  Installed version : ' + version +
      '\n  Fixed version     : ' + fix +
      '\n';

    security_warning(extra:report, port:port);
  }
  else security_warning(port:port);
  exit(0);
}
else audit(AUDIT_INST_VER_NOT_VULN, app_name, version);