interface/globals.php in OpenEMR 2.x, 3.x, and 4.x before 4.2.0 patch 2 allows remote attackers to bypass authentication and obtain sensitive information via an ignoreAuth=1 value to certain scripts, as demonstrated by (1) interface/fax/fax_dispatch_newpid.php and (2) interface/billing/sl_eob_search.php.
http://www.securityfocus.com/bid/75299
http://www.open-emr.org/wiki/index.php/OpenEMR_Patches
http://seclists.org/fulldisclosure/2015/Jun/48
http://packetstormsecurity.com/files/132368/OpenEMR-4.2.0-Authentication-Bypass.html