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Attacking and Enumerating Joomla

Discover the tips and techniques used to attack and break into Joomla based websites. An understanding of these hacker techniques will enable you to be prepared to keep your sites secure.

Additionally, penetration testers or red teams needing to exploit Joomla targets will also find practical hints in this guide.

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Introduction to Joomla Security

Recent statistics show Joomla is a popular open-source Content Management System (CMS), with close to 6% of all websites.

It is open-source, free to download, and easy to use. These things make it a popular option. Similar to WordPress's plugins, Joomla allows functionality through "Extensions"

This popularity makes it a target for bad guys aiming to use a compromised web server for malicious purposes.

A lot of Joomla security holes arise from lack of maintenance, not taking passwords seriously, poorly coded extensions and even site backup's left in the web root.

Enumeration and Reconnaissance

Stage 1 is to discover as much technical information regarding the site configuration. This information is essential as it will aid us as we move onto the actual attacking or exploitation phase.

Now is the time to put yourself in the hacker's mindset. Enumeration or reconnaissance can be conducted stealthily with regular web requests used to gather technical information about the site. Or it can be conducted overtly by aggressively brute-forcing web paths to identify the presence of extensions.

Joomla Identification & Version

To determine if the site is running Joomla, and identify the Joomla Core version, three simple methods can be used to determine the version of Joomla in use.

Meta Generator

Check the HTML source of the page for a meta generator tag in the HEAD section of the HTML source. This is the simplest way to determine if Joomla is being used.

This example is taken from the source of a default Joomla install.

<meta name="generator" content="Joomla! - Open Source Content Management" />

joomla.xml

To identify the version we can check the joomla.xml file within the directory /administrator/manifests/files/

https://www.joomla.org/administrator/manifests/files/joomla.xml

Result

Joomla core version detection

/language/en-GB/en-GB.xml

Another option to find the version is the language file.

https://example.site/language/en-GB/en-GB.xml
<version> 3.6.5 </version>

Version in README.txt

If the meta tag has been disabled, check for the presence of /README.txt from the web root of the install. Joomla has the major version at the top of the ReadMe file.

Joomla readme example

Security Vulnerabilities in Joomla Core

Let's say a site with an older Joomla Core version is discovered by an attacker. This site may be directly exploitable via a security vulnerability in the Joomla core. It also shows the site is not being well maintained.

In a poorly maintained site, other components, such as Extensions or Templates, may not be updated. The likelihood of a successful attack has dramatically improved.

Joomla Extension and version Enumeration

Similar to WordPress's plugins, Joomla allows functionality through "Extensions"
Extensions are broken down into a few types:

  • Modules
  • Components
  • Templates
  • Plugins
  • Languages

All can be installed as required. Vulnerabilities can arise in any of these when poorly coded, an example could be non-logged in users having access to the same features as logged in users.

Enumeration is attempting to find as many installed extensions as we can, including disabled extensions. Knowing these extensions may allow us to identify the version, and research whether it is vulnerable to known exploits.

Unfortunately, unless you have the administrator account details, there is no easy way to find every single extension of a particular Joomla install.

It is worth noting Joomla has a live list called - Vulnerable Extensions List (VEL)
This list is of vulnerable extensions for which no patch is known to exist. It can be used as a source of information or a place to start when looking at a Joomla site.

Passive

Hints to the extensions and modules present in a site may be found in the HTML source of the page. Once, an add-on is identified additional information can be gathered from the manifest file.

Active

Some extensions do not leave traces in the HTML source. To find all the installed extensions you have to be more aggressive. Several tools can brute force known extension/component list. There is no one size fits all when it comes to Joomla. Using a combination of available tools will get the best results.

One example is the Metasploit Joomla Plugin Scanner. This metasploit auxiliary module uses a wordlist to locate valid paths scanning for extensions and vulnerabilities.

Extension Version Enumeration

You have compiled a list of extensions of the site, now for the version. The design of Joomla means this information isn't forthcoming or comprehensive, especially when attempting to find it quietly.

It is possible you may find the extension version in a manifest file or other resources such as the addon's stylesheets or javascript.

With a valid version you can compare what has been found against known exploits. This comparison will attest if the site is likely vulnerable, before throwing any exploits.

Joomla Template Enumeration

As with extensions, Joomla Templates can contain vulnerabilities that may expose the site to compromise. Templates are simply collections of PHP code with HTML and CSS resources. Complex templates have additional components and are more prone to security vulnerabilities.

Enumeration of the template is conducted similarly to detecting the extensions. Inspect the HTML and locate the template. Alternatively, run a passive scan on Hacker Target's Joomla Security Scan and scroll through results to find the Joomla Template.

joomla theme enumeration


One important factor when testing for vulnerable Joomla Templates and components is where it may be installed but not active; as the code is still accessible it may still be vulnerable. For this reason, brute force testing for template paths is an additional step when assessing an unknown Joomla installation.

Enumerate Users

A quick tip is first see if the Administrator login page is publicly available.

https://exampledomain.com/administrator
Gather a list of valid usernames and attempt a password guessing attack to brute force the login credentials. The aim is to gain access to the administrator account. Admin access gives the attacker complete access, and consequently a full compromise of the site, the database, and remote code execution on the server through PHP code execution.

There is no simple way to do this manually in Joomla as opposed to WordPress where it may be possible to iterate through the users using a simple bash one-liner.

Joomla login form

With Joomla, it requires guesswork. All new installs have a 'Super Administrator account' called admin. As part of the install, Joomla requests a password for this account. Joomla also suggests changing the name of the account from 'admin' to something more difficult to guess.

This makes it complicated for a dictionary-based attack against the admin panel.

Enumerating users through Guessing

Start with the common one admin and go from there.

Joomla doesn't seem to allow direct listing all users and / or leak their information.

A default install of Joomla allows 3 privileged user groups which have access to the control panel:

  • Managers: content creation and backend system info.
  • Administrators: admin functions except global options.
  • Super Users/Administrator: ultimate power. Access all areas.

Note: from version 3.2 two-factor authentication was implemented as a core feature. Admins can enable it from User Manager in the Control Panel.

Password Re-use and Breach Datasets


A common technique used in targeted attacks is mining breach datasets for passwords. If a user is breached on another site, there is a chance they will use the same password or a variation on the password on other sites. Working from a targeted domain passwords can quickly be found especially in larger organisations.

Directory Indexing

A misconfigured server can allow you to view the contents of a directory in a web-accessible path.

Viewing the contents of the directory allows an attacker to gather sensitive information not intended for public viewing about the existence and contents of the files. Such as hidden files, backup files, config files, plugins, and templates, without the need to brute force the paths.

Start by browsing to folder locations and see if you get a 200 OK HTTP response and see a list of files / folders in the browser.

Example of directory indexing

Network Service Discovery

Here we are checking network services. The main technique used for identifying the servers attack surface is Port Scanning.

An Nmap port scan will identify the network services listening on the server. These could include FTP, SSH, Webmin or even the web server itself. Working from the results of the Port Scan an attacker would identify server applications, versions and look for exploitation opportunities.

Bypass Sucuri or CloudFlare Web Firewall

If the Joomla site is protected by Sucuri or CloudFlare, exploits that might otherwise succeeed could be blocked. Even various reconnaissance techniques can be blocked by these web based firewall (WAF).

By knowing the real IP address of the server it is likely we could bypass the server simply by putting an entry in the clients /etc/hosts file. This works because we bypass the sites DNS that would otherwise send us via the Web Firewall.

Historical DNS Records

A common method is using historical DNS records to identify the real IP address.

Historical DNS records may show the original IP address before the firewall service was implemented.
Mail Records (MX), if mail is hosted on the same server as the website then this will reveal the real host
TXT SPF, records might also reveal IP addresses of interest

TLS / SSL Certificate Searches

TLS / SSL searches against Certificate Transparency Datasets may also find real hostnames associated with the sites actual IP address if they can matched.

JoomlaVS & Other Tools

Passive Joomla Security Scan

Hacker Target hosts a free and simple to use passive Joomla scan. Discover vulnerabilities, web server details, configuration errors, identify template, and test for directory indexing and others.

The freely available tools perform analysis from a simple page grab. Through the examination of the HTML source code, javascript, and a few other open publicly accessible pages, it is possible to gain immediate insights into the state of security on the target site. This is applying only passive analysis methods, without sending any aggressive security scanning.

JoomScan

JoomScan is the OWASP Joomla! Vulnerability Scanner. An open source project written in Perl. Ties some of these enumeration techniques together such as the Joomla version, vulnerabilities and the admin login page.

Check out the the latest version from github https://github.com/rezasp/joomscan

Note this project has not been updated for a number of years

JoomlaVS

JoomlaVS is an Open source Ruby application. Scan for vulnerabilities in components, modules and templates and basic fingerprinting. More info available on the projects at https://github.com/rastating/joomlavs

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----------------------------------------------------------------------

[+] URL: http://testexample.com/
[+] Started: Mon Jun 12 11:02:01 2020

[+] Found 1 interesting headers.
 |  Server: Apache

[+] Joomla version 2.5.30 identified from language file (en-GB.xml)
[!] Found 8 vulnerabilities affecting this version of Joomla!

[!] Title: Joomla Akeeba Kickstart Unserialize Remote Code Execution
 |  Reference: https://www.exploit-db.com/exploits/35033
 |  Reference: http://www.cvedetails.com/cve/CVE-2014-7228
[i] Fixed in: 3.3.5


[!] Title: Joomla Media Manager File Upload Vulnerability
 |  Reference: https://www.exploit-db.com/exploits/27610
 |  Reference: http://www.cvedetails.com/cve/CVE-2013-5576
[i] Fixed in: 3.1.5


[!] Title: Joomla 2.5.x Language Switcher ModuleMultiple Cross Site Scripting Vulnerabilities
 |  Reference: https://www.exploit-db.com/exploits/37473
[i] Fixed in: 3


[!] Title: Joomla 1.5 - 3.4.5 - Object Injection Remote Command Execution
 |  Reference: https://www.exploit-db.com/exploits/38977
 |  Reference: http://www.cvedetails.com/cve/CVE-2015-8562
[i] Fixed in: 3.4.6


[!] Title: Remote Code Execution in third-party PHPMailer library
 |  Reference: http://www.cvedetails.com/cve/CVE-2016-10033
 |  Reference: http://www.cvedetails.com/cve/CVE-2016-10045
[i] Fixed in: 3.6.5


[!] Title: Unauthorised Logins
 |  Reference: http://www.cvedetails.com/cve/CVE-2014-6632
[i] Fixed in: 3.3.3


[!] Title: Denial of Service
 |  Reference: http://www.cvedetails.com/cve/CVE-2014-7229
[i] Fixed in: 3.3.4


[!] Title: Joomla! < 3.6.4 Privilege Escalation
 |  Reference: http://www.cvedetails.com/cve/CVE-2016-9838
[i] Fixed in: 3.6.4


[+] Scanning for vulnerable components...
[!] Found 0 vulnerable components.

------------------------------------------------------------------

[+] Scanning for vulnerable modules...
[!] Found 0 vulnerable modules.

------------------------------------------------------------------

[+] Scanning for vulnerable templates...
[!] Found 0 vulnerable templates.

------------------------------------------------------------------

[+] Finished

CMSMap

As the name implies, CMSMap covers the most popular of the CMS's. An open source project written in Python, this tool has support for Joomla, WordPress and Drupal. Useful for automating a scan for low-hanging fruit.

Download the latest version of CMSMap github: 

git clone https://github.com/Dionach/CMSmap 

Attacking and Exploitation

Brute Force Joomla logins

2013 Joomla 3.2 stable release bought 2FA as part of the core install which adds another challenge to brute-forcing an account. But it isn't enabled by default.

Popping Weak Passwords

Detecting weak passwords for Joomla comes in a variety of ways. There are many ways to to brute force a login page, here are a few.

Nmap NSE Scripts for Joomla

NMAP is most known for network discovery, however, NSE scripts extend the functionality of the popular NMAP port scanner. An Nmap NSE script is particularly helpful for performing a brute-force password play against a Joomla install.

    $ nmap -p80 http-joomla-brute example-site

Burpsuite

If there is a login form on the site or you have found the administrator interface, then burp suite can be used to try to brute force the password.

There are other tools around such as JoomBrute, and others such as Hydra and Ncrack, though the latter two are most suited for other protocols.

Metasploit

Rapid7's Metasploit provides a few modules for brute forcing CMS and Joomla for various Joomla versions. One is the Joomla Bruteforce login utility

msf > use auxiliary/scanner/http/joomla_bruteforce_login

Exploit Joomla Extensions

One of the most common reasons for Joomla sites being compromised is vulnerable extensions, modules & plugins. These all contain a large amount of PHP code and come from developers of differing levels of skills, abilities, and focus when it comes to writing software that is secure.

Keeping the Joomla extensions, core and templates updated and/or patched needs to be a routine task for the Joomla administrator of the site.


1,437
published exploits for
Joomla and its components

Joomla Security announcements and Vulnerable extensions list

The Joomla Developer Network has a Security Announcements which provides a feed of recently resolved security issues in Joomla software releases.

As part of the Joomla extension directory, Joomla has a list of Vulnerable extensions .

Exploit Example

An issue was discovered in the Creative Contact Form extension (2019). A directory traversal vulnerability resides in the filename field for uploaded attachments. An attacker could exploit this vulnerability with the "Send me a copy" option to receive any files of the filesystem via email.

Exploit References:
https://packetstormsecurity.com/files/156655/Creative-Contact-Form-4.6.2-Directory-Traversal.html
https://nvd.nist.gov/vuln/detail/CVE-2020-9364#VulnChangeHistorySection

Exploit Joomla Template

While vulnerabilities in templates are not as common as extensions, it is still worth checking the template in use. Check the developers page for security related updates, and if its a custom environment running standard web application testing may discover unpublished vulnerabilities.

In this example of an XSS vulnerability, we see that even the Joomla Core Default template had a vulnerability as recently as 2019.

Exploit References:
https://developer.joomla.org/security-centre/791-20190901-core-xss-in-logo-parameter-of-default-templates.html

Exploiting Joomla Core

Vulnerabilities in Joomla Core are highly valued by an Attacker as it does not depend on a particular extension being installed.

In 2016, 2 critical vulnerabilities allowed privilege escalation by remote users. Attackers were first able to create accounts even if account registration is disabled, and 2nd, increase their privileges on any Joomla site using versions 3.4.4 to 3.6.3. Attackers could then upload a backdoor and ultimately control the site.

Solution was the upgrade to version 3.6.4. Joomla devs released limited information on the the vulnerabilities, however it was enough for groups to figure things out and develop exploits. Exploits in the wild were spotted, some included ones that were automatically uploading backdoors to vulnerable sites.

Exploit References:
CVE-2016-8870
CVE-2016-8869
Joomla! 3.4.4 < 3.6.4 - Account Creation / Privilege Escalation

Sniff and Capture Credentials over non-secure login

HTTP over TLS should be enabled on any public website in 2020. If only HTTP is used, passwords, logins and session cookies are all sent over the network in the clear. Clear text sessions could be monitored on your local network, or on your Internet providers network or anywhere between the client and server.

With the easy access to Free certificates there is really no reason to be not using HTTPS. Check your TLS configuration with tools such as sslyze.

Vulnerable Server Software

Exploitation of the Joomla site could come from other server components - it is not always the Joomla Web Application that will be the exploitation vector. A simple misconfiguration of a network service or a failure to apply server updates could lead to compromise of the server and all hosted applications.

With the results of an Nmap scan, an attacker will review open services for known vulnerabilities. A small sample of these network services includes FTP, SSH, MySQL & Redis - any of these could lead to server compromise if vulnerable or poorly configured.

Compromise Systems Administration Tools

Related to the previous section, here we are identifying server applications that may lead to compromise of the Joomla site.

An example of this type of tool is phpmyadmin running on the web server. A weak database password or vulnerable version of phpmyadmin would lead to compromise of the database and possibly even code execution.

Discovery of the phpmyadmin installation would usually involve a content discovery scan that would include common paths for phpmyadmin in the content discovery scanner list.

Content Discovery

Looking for sensitive information, database credentials, backups, are just a few few items that can be found with content discovery. Content discovery is attempting to find any interesting items contained within a web path of an application. There are a variety of tools our there catering for this purpose. Choose the one or ones that suit your needs. A few example tools are; DIRB, dirbustor, dirsearch or gobuster.

Common locations to check are:

    /robot.txt
    /backup
    /images/
    /bin/
    /uploads/
    /components/
    /administrator/
    /.htaccess.txt
    /index.html
    /index.php
    /templates/exampletemplate
    /administrator/templates/exampletemplate
    /phpmyadmin/
    /phpinfo.php

Found Backups

Using content discovery a commonly found vulnerability is a site backup. This results from a mistake during system administration where a backup of the folder was taken and left in the publicly accessible web root (eg. /backup.tar.gz).

With a backup an attacker has access to all files of the installation including all installed components as well as the configuration file containing the database location and password.

PHP info

Another commonly found item during content discovery is a file with the PHP function phpinfo(). Site administrators will often create a file in the root of the site such as /phpinfo.php, the function in this file allows the administrator to know what modules, PHP version and many other server configurations are available on the webserver. This information is also valuable to an attacker if the file is forgotten and left on the server.

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