Time spent: 15 hours spent in total

Objective: Find, analyze, recreate, and document 3 vulnerabilities affecting an old version of WordPress

1. (Required) WordPress 4.2 Stored XSS

• Summary: Bypassing viewing of a comment by injecting javascript. Under default settings the attacker can leverage the vulnerability to execute arbitrary code on the server.

  • Vulnerability types: XSS
  • Tested in version: 4.2
  • Fixed in version: 4.2.1

• GIF Walkthrough:

• Steps to recreate: Post the following in a comment: a title='x onmouseover=alert(unescape(/hello%20world/.source)) style=position:absolute;left:0;top:0;width:5000px;height:5000px AAAAAAAAAAAA...AAA (64kb in size)' /a

                     Make sure the comment is at least 64kb in size. An attacker can supply any type of attribute in HTML tags. 
                     The MySQL TEXT type size limit is 64 kilobytes
  

  • [Link 1] http://wpdistillery.vm/#comment

2. (Required) WordPress Media Upload XSS

• Summary: Uploading a file that is too large results in the filename being unsanitized, leading to XSS
  • Vulnerability types: XSS
  • Tested in version: 4.2
  • Fixed in version: 4.7.5
• GIF Walkthrough:
• Steps to recreate: 1. Get a 20MB image file. Next, name the file "example name (img src=x onerror=alert(1)>).png ... Go to wordpress site and "add new media" (/wp-admin/media-new.php). Once an error appears telling you about the large file size, an alert box will appear showing that the payload has been executed
  • Link 1

3. (Required) Stored XSS Vulnerability when Previewing Posts

• Summary: In the WordPress editor, an administrator or another user with approved permissions can make a post and click "Preview" which allows the HTML, as well as the Javascript to be executed.
  • Vulnerability types: Stored XSS
  • Tested in version: 4.2
  • Fixed in version: 4.8.2
• GIF Walkthrough:
• Steps to recreate: As an administrator or approved user, Go to "Posts" and "Add New". In the "Text" tab, write your payload in the text box section. When you click "Preview" within the "Publish" window on the right, a new tab will be opened and your payload will have been executed.
  • [Link 1] http://wpdistillery.vm/wp-admin/post-new.php

List any additional assets, such as scripts or files

• [WordPress Source Browser] wpdistillery.vm
• WordPress Developer Reference

GIFs created with LiceCap.

Some exploits will only work on Linux, such as #2 above. Otherwise, no problems were encountered while performing the tasks.

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