/usr/share/w3af/plugins/audit/osCommanding.py is in w3af-console 1.0-rc3svn3489-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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osCommanding.py
Copyright 2006 Andres Riancho
This file is part of w3af, w3af.sourceforge.net .
w3af is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation version 2 of the License.
w3af is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with w3af; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
'''
from __future__ import with_statement
import core.controllers.outputManager as om
# options
from core.data.options.option import option
from core.data.options.optionList import optionList
from core.controllers.basePlugin.baseAuditPlugin import baseAuditPlugin
from core.data.fuzzer.fuzzer import createMutants
# kb stuff
import core.data.kb.vuln as vuln
import core.data.kb.info as info
import core.data.constants.severity as severity
import core.data.kb.knowledgeBase as kb
import core.data.kb.config as cf
import re
class osCommanding(baseAuditPlugin):
'''
Find OS Commanding vulnerabilities.
@author: Andres Riancho ( andres.riancho@gmail.com )
'''
def __init__(self):
baseAuditPlugin.__init__(self)
#
# Some internal variables
#
self._special_chars = ['', '&&', '|', ';']
# The wait time of the unfuzzed request
self._original_wait_time = 0
self._file_compiled_regex = []
# The wait time of the first test I'm going to perform
self._wait_time = 4
# The wait time of the second test I'm going to perform (this one is just to be sure!)
self._second_wait_time = 9
def audit(self, freq ):
'''
Tests an URL for OS Commanding vulnerabilities.
@param freq: A fuzzableRequest
'''
om.out.debug( 'osCommanding plugin is testing: ' + freq.getURL() )
# We are implementing two different ways of detecting OS Commanding
# vulnerabilities:
# - Time delays
# - Writing a known file to the HTML output
# The basic idea is to be able to detect ANY vulnerability, so we use ALL
# of the known techniques
self._with_time_delay(freq)
# Wait until the echo tests finish. I need to do this because of an odd problem with
# Python's "with" statement. It seems that if I use two different with statements and
# the same thread lock at the same time, the application locks and stops working.
self._tm.join(self)
self._with_echo(freq)
def _with_time_delay(self, freq):
'''
Tests an URL for OS Commanding vulnerabilities using time delays.
@param freq: A fuzzableRequest
'''
# Send the fuzzableRequest without any fuzzing, so we can measure the response
# time of this script in order to compare it later
res = self._sendMutant( freq, analyze=False, grepResult=False )
self._original_wait_time = res.getWaitTime()
# Prepare the strings to create the mutants
command_list = self._get_wait_commands()
only_command_strings = [ v.getCommand() for v in command_list ]
mutants = createMutants( freq , only_command_strings )
for mutant in mutants:
# Only spawn a thread if the mutant has a modified variable
# that has no reported bugs in the kb
if self._hasNoBug( 'osCommanding' , 'osCommanding', mutant.getURL() , mutant.getVar() ):
targs = (mutant,)
kwds = {'analyze_callback':self._analyze_wait}
self._tm.startFunction( target=self._sendMutant, args=targs , \
kwds=kwds, ownerObj=self )
self._tm.join( self )
def _with_echo(self, freq):
'''
Tests an URL for OS Commanding vulnerabilities using cat/type to write the
content of a known file (i.e. /etc/passwd) to the HTML.
@param freq: A fuzzableRequest
'''
original_response = self._sendMutant( freq , analyze=False ).getBody()
# Prepare the strings to create the mutants
command_list = self._get_echo_commands()
only_command_strings = [ v.getCommand() for v in command_list ]
mutants = createMutants( freq , only_command_strings, oResponse=original_response )
for mutant in mutants:
# Only spawn a thread if the mutant has a modified variable
# that has no reported bugs in the kb
if self._hasNoBug( 'osCommanding' , 'osCommanding', mutant.getURL() , mutant.getVar() ):
targs = (mutant,)
kwds = {'analyze_callback':self._analyze_echo}
self._tm.startFunction( target=self._sendMutant, args=targs , \
kwds=kwds, ownerObj=self )
def _analyze_echo( self, mutant, response ):
'''
Analyze results of the _sendMutant method that was sent in the _with_echo method.
'''
#
# Only one thread at the time can enter here. This is because I want to report each
# vulnerability only once, and by only adding the "if self._hasNoBug" statement, that
# could not be done.
#
with self._plugin_lock:
#
# I will only report the vulnerability once.
#
if self._hasNoBug( 'osCommanding' , 'osCommanding' , mutant.getURL() , mutant.getVar() ):
file_patterns = self._get_file_patterns()
for file_pattern_re in file_patterns:
match = file_pattern_re.search( response.getBody() )
if match\
and not file_pattern_re.search( mutant.getOriginalResponseBody() ):
# Search for the correct command and separator
sentOs, sentSeparator = self._get_os_separator(mutant)
# Create the vuln obj
v = vuln.vuln( mutant )
v.setName( 'OS commanding vulnerability' )
v.setSeverity(severity.HIGH)
v['os'] = sentOs
v['separator'] = sentSeparator
v.setDesc( 'OS Commanding was found at: ' + mutant.foundAt() )
v.setDc( mutant.getDc() )
v.setId( response.id )
v.setURI( response.getURI() )
v.addToHighlight( match.group(0) )
kb.kb.append( self, 'osCommanding', v )
break
def _get_file_patterns(self):
'''
@return: A list of file patterns, that if found in the response, indicate that a command
was successfully executed.
'''
if self._file_compiled_regex:
# returning the already compiled regular expressions
return self._file_compiled_regex
else:
# Compile them for the first time, and return the compiled regular expressions
file_patterns = []
# /etc/passwd
file_patterns.append("root:x:0:0:")
file_patterns.append("daemon:x:1:1:")
file_patterns.append(":/bin/bash")
file_patterns.append(":/bin/sh")
# /etc/passwd in AIX
file_patterns.append("root:!:x:0:0:")
file_patterns.append("daemon:!:x:1:1:")
file_patterns.append(":usr/bin/ksh")
# boot.ini
file_patterns.append("\\[boot loader\\]")
file_patterns.append("default=multi\\(")
file_patterns.append("\\[operating systems\\]")
# win.ini
file_patterns.append("\\[fonts\\]")
self._file_compiled_regex = [re.compile(i, re.IGNORECASE) for i in file_patterns]
return self._file_compiled_regex
def _get_os_separator(self, mutant):
'''
@parameter mutant: The mutant that is being analyzed.
@return: A tuple with the OS and the command separator
that was used to generate the mutant.
'''
# Retrieve the data I need to create the vuln and the info objects
command_list = self._get_echo_commands()
command_list.extend( self._get_wait_commands() )
### BUGBUG: Are you sure that this works as expected?!?!?!
for comm in command_list:
if comm.getCommand() in mutant.getModValue():
sentOs = comm.getOs()
sentSeparator = comm.getSeparator()
return sentOs, sentSeparator
def _analyze_wait( self, mutant, response ):
'''
Analyze results of the _sendMutant method that was sent in the _with_time_delay method.
'''
#
# Only one thread at the time can enter here. This is because I want to report each
# vulnerability only once, and by only adding the "if self._hasNoBug" statement, that
# could not be done.
#
with self._plugin_lock:
#
# I will only report the vulnerability once.
#
if self._hasNoBug( 'osCommanding' , 'osCommanding' , mutant.getURL() , mutant.getVar() ):
if response.getWaitTime() > (self._original_wait_time + self._wait_time-2) and \
response.getWaitTime() < (self._original_wait_time + self._wait_time+2):
sentOs, sentSeparator = self._get_os_separator(mutant)
# This could be because of an osCommanding vuln, or because of an error that
# generates a delay in the response; so I'll resend changing the time and see
# what happens
original_wait_param = mutant.getModValue()
more_wait_param = original_wait_param.replace( \
str(self._wait_time), \
str(self._second_wait_time) )
mutant.setModValue( more_wait_param )
response = self._sendMutant( mutant, analyze=False )
if response.getWaitTime() > (self._original_wait_time + self._second_wait_time-3) and \
response.getWaitTime() < (self._original_wait_time + self._second_wait_time+3):
# Now I can be sure that I found a vuln, I control the time of the response.
v = vuln.vuln( mutant )
v.setName( 'OS commanding vulnerability' )
v.setSeverity(severity.HIGH)
v['os'] = sentOs
v['separator'] = sentSeparator
v.setDesc( 'OS Commanding was found at: ' + mutant.foundAt() )
v.setDc( mutant.getDc() )
v.setId( response.id )
v.setURI( response.getURI() )
kb.kb.append( self, 'osCommanding', v )
else:
# The first delay existed... I must report something...
i = info.info()
i.setName('Possible OS commanding vulnerability')
i.setId( response.id )
i.setDc( mutant.getDc() )
i.setMethod( mutant.getMethod() )
i['os'] = sentOs
i['separator'] = sentSeparator
msg = 'A possible OS Commanding was found at: ' + mutant.foundAt()
msg += 'Please review manually.'
i.setDesc( msg )
kb.kb.append( self, 'osCommanding', i )
def end(self):
'''
This method is called when the plugin wont be used anymore.
'''
self._tm.join( self )
self.printUniq( kb.kb.getData( 'osCommanding', 'osCommanding' ), 'VAR' )
def _get_echo_commands(self):
'''
@return: This method returns a list of commands to try to execute in order
to print the content of a known file.
'''
commands = []
for special_char in self._special_chars:
# Unix
cmd_string = special_char + "/bin/cat /etc/passwd"
commands.append( command(cmd_string, 'unix', special_char))
# Windows
cmd_string = special_char + "type %SYSTEMROOT%\\win.ini"
commands.append( command(cmd_string, 'windows', special_char))
# Execution quotes
commands.append( command("`/bin/cat /etc/passwd`", 'unix', '`'))
# FoxPro uses run to run os commands. I found one of this vulns !!
commands.append( command("run type %SYSTEMROOT%\\win.ini", 'windows', 'run'))
# Now I filter the commands based on the targetOS:
targetOS = cf.cf.getData('targetOS').lower()
commands = [ c for c in commands if c.getOs() == targetOS or targetOS == 'unknown']
return commands
def _get_wait_commands( self ):
'''
@return: This method returns a list of commands to try to execute in order
to introduce a time delay.
'''
commands = []
for special_char in self._special_chars:
# Windows
cmd_string = special_char + 'ping -n '+str(self._wait_time -1)+' localhost'
commands.append( command( cmd_string, 'windows', special_char))
# Unix
cmd_string = special_char + 'ping -c '+str(self._wait_time)+' localhost'
commands.append( command( cmd_string, 'unix', special_char))
# This is needed for solaris 10
cmd_string = special_char + '/usr/sbin/ping -s localhost 1000 10 '
commands.append( command( cmd_string, 'unix', special_char))
# Using execution quotes
commands.append( command( '`ping -n '+str(self._wait_time -1)+' localhost`', 'windows', '`'))
commands.append( command( '`ping -c '+str(self._wait_time)+' localhost`', 'unix', '`'))
# FoxPro uses the "run" macro to exec os commands. I found one of this vulns !!
commands.append( command( 'run ping -n '+str(self._wait_time -1)+' localhost', 'windows', 'run '))
# Now I filter the commands based on the targetOS:
targetOS = cf.cf.getData('targetOS').lower()
commands = [ c for c in commands if c.getOs() == targetOS or targetOS == 'unknown']
return commands
def getOptions( self ):
'''
@return: A list of option objects for this plugin.
'''
ol = optionList()
return ol
def setOptions( self, OptionList ):
'''
This method sets all the options that are configured using the user interface
generated by the framework using the result of getOptions().
@parameter OptionList: A dictionary with the options for the plugin.
@return: No value is returned.
'''
pass
def getPluginDeps( self ):
'''
@return: A list with the names of the plugins that should be runned before the
current one.
'''
return []
def getLongDesc( self ):
'''
@return: A DETAILED description of the plugin functions and features.
'''
return '''
This plugin will find OS commanding vulnerabilities. The detection is performed using two different techniques:
- Time delays
- Writing a known file to the HTML output
With time delays, the plugin sends specially crafted requests that, if the vulnerability is present, will delay
the response for 5 seconds (ping -c 5 localhost).
When using the second technique, the plugin sends specially crafted requests that, if the vulnerability is present,
will print the content of a known file (i.e. /etc/passwd) to the HTML output
This plugin has a rather long list of command separators, like ";" and "`" to try to match all programming languages,
platforms and installations.
'''
# I define this here, because it is used by the _get_echo_commands
# and _get_wait_commands methods.
class command:
'''
Defines a command that is going to be sent to the remote web app.
'''
def __init__( self, comm, os, sep ):
self._comm = comm
self._os = os
self._sep = sep
def getOs( self ):
'''
@return: The OS
'''
return self._os
def getCommand( self ):
'''
@return: The Command to be executed
'''
return self._comm
def getSeparator( self ):
'''
@return: The separator, could be one of ; && | etc.
'''
return self._sep
|