iOpus Secure Email Attachments (SEA), probably 1.0, does not properly handle passwords that consist of repetitions of a substring, which allows attackers to decrypt files by entering only the substring.
https://exchange.xforce.ibmcloud.com/vulnerabilities/26266
http://www.securityfocus.com/bid/17656
http://www.securityfocus.com/archive/1/431989/100/0/threaded
http://www.securityfocus.com/archive/1/431904/100/0/threaded