Summary

In this chapter, we looked at how the Linux operating system’s basic filesystem directories are set up. We also looked at how Linux authentication and permissions work as well as some of the areas in which attackers can take advantage, such as SUID and world-writable files. We also took a brief look at password cracking in Linux, system misconfigurations, and software vulnerabilities. We also discussed patching, and making sure the latest software and patches are installed. Once an attacker determines you’re running a vulnerable version of the software, the exploit is all but guaranteed. We also touched on services, spending time understanding the server’s purpose, which will determine what services should be running and then disable and/or remove the services not needed. This will reduce the attack surface, leaving the attacker less avenues to attack.

In the next chapter, we will look at common applications and services that span both Windows and Linux...