SNMP

Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behavior. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more.

SNMP is widely used in network management for network monitoring. SNMP exposes management data in the form of variables on the managed systems organized in a management information base (MIB) which describe the system status and configuration. These variables can then be remotely queried (and, in some circumstances, manipulated) by managing applications.

Exploit

SNMPv1 and SNMPv2 authentication is nothing more than a community string which is sent in clear-text between the manager and the agent. SNMPv3 uses strong passwords and the authentication protocol set the SHA. Most SNMP implementations ship with a default "read-only" community string of "public" or even a writable string of "private", which could enable the modifications of SNMP agent variables.