Citrix Published Applications Enumeration (UDP)

# SPDX-FileCopyrightText: 2002 John [email protected]
# 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-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.11138");
  script_version("2025-03-19T05:38:35+0000");
  script_tag(name:"last_modification", value:"2025-03-19 05:38:35 +0000 (Wed, 19 Mar 2025)");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_name("Citrix Published Applications Enumeration (UDP)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2002 John [email protected]");
  script_family("General");
  script_require_udp_ports(1604);

  script_xref(name:"URL", value:"https://web.archive.org/web/20061225071711/http://sh0dan.org:80/files/hackingcitrix.txt");
  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/5817");
  script_xref(name:"URL", value:"http://www.securiteam.com/exploits/5CP0B1F80S.html");

  script_tag(name:"summary", value:"UDP based enumeration of Citrix published applications.");

  script_tag(name:"impact", value:"The Citrix server is configured in a way which may allow an
  external attacker to enumerate remote services.");

  script_tag(name:"solution", value:"See the references on how to secure the Citrix installation.");

  script_tag(name:"qod_type", value:"remote_active");
  script_tag(name:"solution_type", value:"Workaround");

  exit(0);
}

port = 1604;
if( ! get_udp_port_state( port ) )
  exit( 0 );

if( ! soc = open_sock_udp( port ) )
  exit( 0 );

trickmaster  = raw_string( 0x20, 0x00, 0x01, 0x30, 0x02, 0xFD, 0xA8, 0xE3 );
trickmaster += raw_string( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 );
trickmaster += raw_string( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 );
trickmaster += raw_string( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 );

send( socket:soc, data:trickmaster );
res = recv( socket:soc, length:1024 );
close( soc );
if( ! res )
  exit( 0 );

if( ! soc = open_sock_udp( port ) )
  exit( 0 );

get_pa  = raw_string( 0x2A, 0x00, 0x01, 0x32, 0x02, 0xFD );
get_pa += raw_string( 0xa8, 0xe3, 0x00, 0x00, 0x00, 0x00 );
get_pa += raw_string( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 );
get_pa += raw_string( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 );
get_pa += raw_string( 0x00, 0x00, 0x00, 0x00, 0x21, 0x00 );
get_pa += raw_string( 0x02, 0x00, 0x00, 0x00, 0x00, 0x00 );
get_pa += raw_string( 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 );

send( socket:soc, data:get_pa );
res = recv( socket:soc, length:1024 );
close( soc );
if( ! res )
  exit( 0 );

if( res =~ '\x02\x00\x06\x44' ) {
  security_message( port:port, proto:"udp" );
  exit( 0 );
}

exit( 99 );