Meridian Prolog Manager 2007, and 7.5 and earlier, sends all usernames and passwords to the client in a (1) cleartext or (2) weakly encrypted format to support client-side login authentication, which makes it easier for remote attackers to obtain database access by capturing credentials via a man-in-the-middle attack.
https://exchange.xforce.ibmcloud.com/vulnerabilities/38996
http://www.securityfocus.com/bid/26826
http://www.securityfocus.com/archive/1/484886/100/0/threaded
http://www.kb.cert.org/vuls/id/MIMG-77FL3T
http://www.kb.cert.org/vuls/id/120593