IBM WebSphere MQ 6.0 before 6.0.2.9 and 7.0 before 7.0.1.1 does not encrypt the username and password in the security parameters field, which allows remote attackers to obtain sensitive information by sniffing the network traffic from a .NET client application.
https://exchange.xforce.ibmcloud.com/vulnerabilities/63114
http://www-01.ibm.com/support/docview.wss?uid=swg27014224