sqlmap/tamper/ifnull2ifisnull.py
2012-12-03 14:27:01 +01:00

65 lines
1.6 KiB
Python

#!/usr/bin/env python
"""
Copyright (c) 2006-2012 sqlmap developers (http://sqlmap.org/)
See the file 'doc/COPYING' for copying permission
"""
from lib.core.enums import PRIORITY
__priority__ = PRIORITY.HIGHEST
def dependencies():
pass
def tamper(payload, **kwargs):
"""
Replaces instances like 'IFNULL(A, B)' with 'IF(ISNULL(A), B, A)'
Example:
* Input: IFNULL(1, 2)
* Output: IF(ISNULL(1), 2, 1)
Requirement:
* MySQL
* SQLite (possibly)
* SAP MaxDB (possibly)
Tested against:
* MySQL 5.0 and 5.5
Notes:
* Useful to bypass very weak and bespoke web application firewalls
that filter the IFNULL() function
"""
if payload and payload.find("IFNULL") > -1:
while payload.find("IFNULL(") > -1:
index = payload.find("IFNULL(")
depth = 1
comma, end = None, None
for i in xrange(index + len("IFNULL("), len(payload)):
if depth == 1 and payload[i] == ',':
comma = i
elif depth == 1 and payload[i] == ')':
end = i
break
elif payload[i] == '(':
depth += 1
elif payload[i] == ')':
depth -= 1
if comma and end:
_ = payload[index + len("IFNULL("):comma]
__ = payload[comma + 1:end]
newVal = "IF(ISNULL(%s),%s,%s)" % (_, __, _)
payload = payload[:index] + newVal + payload[end+1:]
else:
break
return payload