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Syhunt: Time-Based Blind NoSQL Injection

Time-Based Blind NoSQL Injection - Detecting server-side JavaScript injection vulnerabilities

In July 2011, Bryan Sullivan, a senior security researcher at Adobe Systems, demonstrated server-side JavaScript injection vulnerabilities in web applications using MongoDB and other NoSQL database engines. He demonstrated how they could be used to perform Denial of Service, File System, Remote Command Execution, and many other attacks, including the easy extraction of the entire contents of the NoSQL database -- a blind NoSQL injection attack (paper here at https://media.blackhat.com/bh-us-11/Sullivan/BH_US_11_Sullivan_Server_Side_WP.pdf).

We not only confirmed the published data about the NoSQL injection vulnerabilities, but also discovered that the MongoDB shell provides a sleep() function which makes time-based detection possible of vulnerable web applications.

It is also possible to inject a custom sleep code, a technique that may be used to spot injection vulnerabilities in web applications using server-side JavaScript execution. This is not restricted to MongoDB.

Below you can find two examples of NoSQL injection vulnerabilities in PHP that could be spotted using these techniques.

Example 1: NoSQL Injection Vulnerability in PHP

The following requests would make these (or similar) vulnerable web application sleep for 10 seconds:


The MongoDB sleep() function works with milliseconds.

Alternative technique using a custom sleep code:


$mongo = new Mongo();
$db = $mongo->demo;
$id = $_GET['id'];
$js = "function() {
var id = '$id';
$response = $db->execute($js);

Example 2: NoSQL Injection Vulnerability in PHP

$mongo = new Mongo();
$db = $mongo->demo;
$year = $_GET['year'];
$collection = $db->demo;
$query = 'function() {var search_year = \'' .
$year . '\';' .
'return this.publicationYear == search_year || ' .
' this.filmingYear == search_year || ' .
' this.recordingYear == search_year;}';
$cursor = $collection->find(array('$where' => $query));

Example 3: Sleep in JavaScript

var date = new Date();
var curDate = null;
do { curDate = new Date(); }
while(curDate-date < 10000); // delay time (ms)


Always validate user input used in server-side JavaScript commands.

Article by Felipe Aragon. Originally published at http://www.syhunt.com/?n=Articles.NoSQLInjection


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