CMS Security Handbook: The Comprehensive Guide for WordPress®, Joomla!®, Drupal™, and Plone®

Securing SNMP

Simple Network Management Protocol (SNMP) allows a machine (such as a server) to communicate its status to an application. Things that can be communicated from servers typically include temperature of the machine, the speed and operation of cooling fans, the output of the power supplies, and more.

An administrator can remotely manage the server using SNMP. This is a typical setup in many hosting situations where the administrators are physically present in the data center. Many hardware manufacturers such as Dell, Hewlett-Packard, IBM, and others support this protocol, and offer tools to monitor and manage servers.

Overall, SNMP can be considered a weakness, and should be shut off if it's not in use. However, if you are renting a server from a hosting company or a co-location facility, you likely won't be able to shut this protocol off on your own. What you want to be sure of, however, is that if in use, it's configured as securely as possible.

One classic weakness is that the Community string is often left at public. In essence, the Community string is the password to the system. With it, you can read and write to the machine in question, and because default passwords are prevalent in the computer industry, chances are good that the SNMP password is set to public on many machines out there today.

SNMP has two parts that you'll interact with:

• The Management Information Base (MIB) contains the description and controls for various devices in the server, networking ...