IBM WebSphere Portal 8.0.0 before 8.0.0.1 CF13 and 8.5.0 through CF01 provides different error codes for firewall-traversal requests depending on whether the intranet host exists, which allows remote attackers to map the intranet network via a series of requests.
https://exchange.xforce.ibmcloud.com/vulnerabilities/94348
http://www.securitytracker.com/id/1030669
http://www-01.ibm.com/support/docview.wss?uid=swg21680230