Variable overwrite vulnerability in interface/globals.php in OpenEMR 2.8.2 and earlier allows remote attackers to overwrite arbitrary program variables and conduct other unauthorized activities, such as conduct (a) remote file inclusion attacks via the srcdir parameter in custom/import_xml.php or (b) cross-site scripting (XSS) attacks via the rootdir parameter in interface/login/login_frame.php, via vectors associated with extract operations on the (1) POST and (2) GET superglobal arrays.  NOTE: this issue was originally disputed before the extract behavior was identified in post-disclosure analysis. Also, the original report identified "Open Conference Systems," but this was an error.