The wp_create_nonce function in wp-includes/pluggable.php in WordPress 3.3.1 and earlier associates a nonce with a user account instead of a user session, which might make it easier for remote attackers to conduct cross-site request forgery (CSRF) attacks on specific actions and objects by sniffing the network, as demonstrated by attacks against the wp-admin/admin-ajax.php and wp-admin/user-new.php scripts. NOTE: the vendor reportedly disputes the significance of this issue because wp_create_nonce operates as intended, even if it is arguably inconsistent with certain CSRF protection details advocated by external organizations
http://www.webapp-security.com/2012/04/wordpress-3-3-1-multiple-csrf-vulnerabilities