============================================= INTERNET SECURITY AUDITORS ALERT 2008-001 - Original release date: January 3rd, 2008 - Last revised: December 22nd, 2008 - Discovered by: Jesus Olmos Gonzalez - Severity: 2/5 =============================================
Wordpress is vulnerable to an unauthorized upgrade and XSS
WordPress started in 2003 with a single bit of code to enhance the typography of everyday writing and with fewer users than you can count on your fingers and toes. Since then it has grown to be the largest self-hosted blogging tool in the world, used on hundreds of thousands of sites and seen by tens of millions of people every day. With a very active development and evolution.
If the WordPress is not the last version, anybody can upgrades the aplication using wp-admin/upgrade.php
The snippet of vulnerable code:
if (isset($_GET['step'])) $step = (int) $_GET['step']; ... switch($step) : case 0: $goback = clean_url(stripslashes(wp_get_referer())); ... case 1: wp_upgrade(); if ( empty( $_GET['backto'] ) ) $backto = __get_option('home') . '/'; ...
If step is set to one, the link "Have fun" is set to the backto parameter value, then is possible to make a Cross Site Attack to steal user sessions.
If the upgrade fails, the availibility of the wordpress could be affected. If the cross site attack succeeds, the confidentiality and integrity of the content will be afected.
All versions of wordpress are affected.
Wordpress considered was not as serious as it seams. So no patch published for this issue.
This vulnerability has been discovered and reported by Jesus Olmos Gonzalez (jolmos (at) isecauditors (dot) com).
December 21, 2007: Initial release January 7, 2008: More details added.
December 21, 2007: Vulnerability acquired by Internet Security Auditors (www.isecauditors.com) January 6, 2008: WordPress security contacted. January 11, 2008: WordPress security confirms they consider the vulnerability as low impact. December 22, 2008: Published
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