write_ok.php in Zeroboard 4.1 pl8, when installed on Apache with mod_mime, allows remote attackers to bypass restrictions for uploading files with executable extensions by uploading a .htaccess file that with an AddType directive that assigns an executable module to files with assumed-safe extensions, as demonstrated by assigning the txt extension to be handled by application/x-httpd-php.
https://exchange.xforce.ibmcloud.com/vulnerabilities/27038
http://www.vupen.com/english/advisories/2006/2318
http://www.securityfocus.com/bid/18465
http://www.securityfocus.com/archive/1/437442/30/4320/threaded