Unix® System Management Primer Plus

Simple Ways to Improve Your Security

Now that you are familiar with many of the security issues with Unix systems, you are ready to learn the following simple techniques for securing your systems:

• Minimizing the number of setuid programs on your system

• Removing world-writable permissions

• Installing TCP wrappers

• Removing unnecessary services from inetd

• Requiring secure passwords

• Monitoring the integrity of your file systems

Each of these techniques is applicable to any Unix operating system, so you should find them useful for every system you administer. The following sections discuss these techniques in detail.

Minimizing the Number of setuid Programs

setuid programs execute with the permissions of the owner of the executable file, so when setuid ...