This overview of RedHat Linux security is a bit out-of-date so just take a glimpse to see what's involved but I recommend that you refer to a more comprehensive and up-to-date resource such as www.cert.org. Sep. 19, 2000
These are slides and handouts used in the "Improving Security on Your Linux Box" talk, given at UTCS (GRIT; GRACS Implementation Topics), arranged by the UTCS Grad student committee (GRACS).