On Fri, Jun 07, 2013 at 06:29:48PM +0200, Krzysztof Katowicz-Kowalewski wrote: > Version 3.5.1 (latest) of popular blogging engine WordPress suffers from remote denial of service vulnerability. The bug exists in encryption module (class-phpass.php). The exploitation of this vulnerability is possible only when at least one post is protected by a password. > > Time frames: > 31.05.2013 WordPress security team has been informed about the vulnerability (no response). > 07.06.2013 The vulnerability has been released to the public. > > More information (including proof of concept): > https://vndh.net/note:wordpress-351-denial-service > > A way out (before official WordPress update) to secure existing installations is to apply the following patch: > > --- wp-includes/class-phpass.php > +++ wp-includes/class-phpass.php > @@ -120,7 +120,7 @@ > return $output; > > $count_log2 = strpos($this->itoa64, $setting[3]); > - if ($count_log2 < 7 || $count_log2 > 30) > + if ($count_log2 < 7 || $count_log2 > 13) > return $output; > > $count = 1 << $count_log2; Hi, This phpass.php isn't hand-rolled like you stated in your blog post; it's a copy of a public domain crypt()-workalike: http://www.openwall.com/phpass/ There are several other systems which implement their password hashing using this library. Having said that, being able to control the setting looks like a mistake on the part of Wordpress, so I'm not sure the bug is in phpass, strictly speaking. However, have you considered contacting upstream (Solar Designer/OpenWall) about this? Cheers, Peter -- http://www.more-magic.net
