Custom Vulnerability Object to detect Failed WordPress Logins

[SimonBlackler]

I'm trying to stem the flood of wordpress brute force attacks coming into our network (we host a lot of WP sites).

Detecting WP logins is relatively easy, by setting up a signature that looks for the regex wp\-login\.php in the http-req-uri-path context with the http-method = POST qualifier. I can now see all of the wp-login requests coming into our network.

However, detecting a failed WP means also detecting the 200 response code from the web server (WordPress issues a 302 redirect upon sucessful login, a 200 upon failure).

I have tried adding an extra AND condition to my signature which checks for http-rsp-code = 200 but it doesn't trigger. So...

Custom Vuln Signature:

Severity : Informational

Default Action : Alert

Direction : client2server

Affected System : server

Signature (Standard)

Scope : Transaction

Ordered Condition Match

Condition 1 : pattern-match http-req-uri-path ~= wp\-login\.php

Condition 2 : equal-to http-rsp-code == 200

Why is this failing to work? Without Condition 2 it shows up all wp logins, but with Condition 2 it sees nothing. Help 🙂

[HULK]

Hello Simonblackler,

Could you please post your query to DEVCENTER, they might help you for your custom signature.

Thanks

[HITSSEC]

Simon,

We control wordpress logins in the following manner:

force your web content management staff us only access the Wordpress login page from on the network (internal zone) and if they require it from of the network then require them to use a vpn solution.   This then means that any wordpress login request from the internet is not desirable and can be blocked with the signature that just identifies the incoming request from the internet.  We have been doing this for over a year now with a lot of success.

Phil

[SimonBlackler]

Thanks Phil, unfortunately this won't work - we are a web host and host thousands of wp sites - we need to block/reset incoming connections from external/public IP addresses that repeatedly fail to log into WP correctly.

[pulukas]

The signature does look correct for the response code 200.  Can you do a packet capture on a failed login and confirm what the data looks like in the response?