[Full-disclosure] Bypass the Stop User Enumeration WordPress Plugin

[Andrew Horton <horton.nz@xxxxxxxxx>]

Stop User Enumeration is a WordPress plugin that provides protection
against an unauthenticated attacker gaining a list of all WordPress users.
This information can aid an attacker in further attacks against the website
including brute-force password guessing attacks. This can be performed
using wp-scan.
Homepage: http://wordpress.org/plugins/stop-user-enumeration/
Version: 1.2.4 (latest)

According to the full disclosure methodology  I have publicly disclosed
this at the same time as notifying the vendor.

Advisory
-------------
An attacker can bypass the username enumeration protection by using POST
requests. The protection currently only stops GET requests to enumerate
users.

By sending POST requests with the body of "author=1" and incrementing the
number over successive requests, the entire set of WordPress users can be
enumerated.

The WordPress user information is disclosed in the HTML response body,
unlike being disclosed in the redirect header, as with GET requests.

   1.

   POST / HTTP/1.1
   Host: www.wordpress.com
   Content-Type: application/x-www-form-urlencoded
   Content-Length: 8

   author=1











Andrew Horton (urbanadventurer)
www.morningstarsecurity.com

Visit my meta-aggregator of security news at
http://www.morningstarsecurity.com/news/

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