WordPress 2.9 before 2.9.2 allows remote authenticated users to read trash posts from other authors via a direct request with a modified p parameter.
https://core.trac.wordpress.org/ticket/11236
http://wordpress.org/development/2010/02/wordpress-2-9-2/
http://secunia.com/advisories/42871
http://secunia.com/advisories/38592
http://lists.fedoraproject.org/pipermail/package-announce/2011-January/052932.html
http://lists.fedoraproject.org/pipermail/package-announce/2011-January/052917.html
http://hakre.wordpress.com/2010/02/16/the-short-memory-of-wordpress-org-security/