'''
buffOverflow.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 core.data.fuzzer.fuzzer import *
import core.controllers.outputManager as om
from core.controllers.basePlugin.baseAuditPlugin import baseAuditPlugin
from core.controllers.w3afException import w3afException
import core.data.parsers.urlParser as urlParser
import core.data.kb.knowledgeBase as kb
import core.data.kb.vuln as vuln
class buffOverflow(baseAuditPlugin):
'''
This plugin tests for buffer overflow bugs.
@author: Andres Riancho ( andres.riancho@gmail.com )
'''
'''
Some notes:
On apache, when an overflow happends on a cgic script, this is written to the log:
*** stack smashing detected ***: /var/www/w3af/bufferOverflow/buffOverflow.cgi terminated, referer: http://localhost/w3af/bufferOverflow/buffOverflow.cgi
Premature end of script headers: buffOverflow.cgi, referer: http://localhost/w3af/bufferOverflow/buffOverflow.cgi
On apache, when an overflow happends on a cgic script, this is returned to the user:
500 Internal Server Error
Internal Server Error
The server encountered an internal error or
misconfiguration and was unable to complete
your request.
Please contact the server administrator,
webmaster@localhost and inform them of the time the error occurred,
and anything you might have done that may have
caused the error.
More information about this error may be available
in the server error log.
Apache/2.0.55 (Ubuntu) mod_python/3.2.8 Python/2.4.4c1 PHP/5.1.6 Server at localhost Port 80
Note that this is an apache error 500, not the more common PHP error 500.
'''
def __init__(self):
baseAuditPlugin.__init__(self)
def _fuzzRequests(self, freq ):
'''
Tests an URL for buffer overflow vulnerabilities.
@param freq: A fuzzableRequest
'''
om.out.debug( 'bufferOverflow plugin is testing: ' + freq.getURL() )
strList = self._getStringList()
mutants = createMutants( freq , strList )
for mutant in mutants:
targs = (mutant,)
self._tm.startFunction( target=self._sendMutant, args=targs, ownerObj=self )
def _getStringList( self ):
'''
@return: This method returns a list of strings that could overflow a buffer.
'''
strings = []
lengths = [ 65 , 257 , 513 , 1025, 2049 ]
### TODO !! if lengths = [ 65 , 257 , 513 , 1025, 2049, 4097, 8000 ]
### then i get a badStatusLine exception from urllib2, is seems to be a internal error.
### tested against tomcat 5.5.7
for l in lengths:
strings.append( createRandAlpha( l ) )
return strings
def _analyzeResult( self, mutant, response ):
'''
Analyze results of the _sendMutant method.
'''
for error in self._getErrors():
# hmmm...
if response.getBody().count( error ):
v = vuln.vuln( mutant )
v.setId( response.id )
v.setDesc( 'A possible buffer overflow (detection is really hard...) was found at: ' + response.getURL() + ' . Using method: ' + v.getMethod() + '. The data sent was: ' + str(mutant.getDc()) )
kb.kb.append( self, 'buffOverflow', v )
def end(self):
'''
This method is called when the plugin wont be used anymore.
'''
self._tm.join( self )
self.printUniq( kb.kb.getData( 'buffOverflow', 'buffOverflow' ), 'VAR' )
def _getErrors( self ):
res = []
res.append('\n500 Internal Server Error\n\nInternal Server Error
')
return res
def getOptionsXML(self):
'''
This method returns a XML containing the Options that the plugin has.
Using this XML the framework will build a window, a menu, or some other input method to retrieve
the info from the user. The XML has to validate against the xml schema file located at :
w3af/core/ui/userInterface.dtd
@return: XML with the plugin options.
'''
return '\
\
\
'
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 getOptionsXML().
@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 buffer overflow vulnerabilities.
Users have to know that detecting a buffer overflow vulnerability will be only possible if the server is configured
to return errors, and the application is developed in cgi-c or some other language that allows the programmer to
do their own memory management.
'''