List of some APIs present in SDN controllers to obtain sensitive information.

enum_controllers

FloodLight port 8080:
/wm/core/controller/switches/json - List of all switch DPIDs connected to the controller
/wm/core/controller/summary/json - Controller summary (# of Switches, # of Links, etc)
/wm/core/memory/json - Current controller memory usage
/wm/core/health/json - Status/Health of REST API
/wm/core/system/uptime/json - Controller uptime
/wm/topology/external-links/json - Show "external" links, i.e., multi-hop links discovered by BDDP instead of LLDP packets 
/wm/topology/links/json - Show DIRECT and TUNNEL links discovered based on LLDP packets
/wm/staticflowentrypusher/list/all/json - List static flows for a switch or all switches
/wm/firewall/rules/json - List all existing rules in json format
/wm/firewall/module/status/json - Show whether the firewall is enabled or disabled.

OpenDayLight port 8080:
/rest/v1/model/controller-node

HP VAN SDN port 8443:
/sdn/v2.0/models

Juniper Contrail port 8081/8082:
/analytics/uves

IBM SDN-VE port 8443:
/one/nb/v2

Cisco XNC port 8080:
/controller/nb/v2/monitor

Soon a more complete list...