Protecting the Internal Attack Surface
Inside Job
© Lead Image © peshkov, 123RF.com
Security is more than a firewall. The biggest worry is what happens when an intruder gets inside. We take a look at some common misconfiguration issues that can lead to privilege escalation.
When configuring and deploying a new machine, security is a primary consideration. Most security analyses focus on vulnerabilities in network-facing services. Activities such as updating the kernel to the latest stable version, configuring a perimeter firewall, and implementing Multi-Factor Authentication for SSH access are now standard practices for any system administrator.
Yet, many Linux servers considered "hardened" hide often-overlooked systemic vulnerabilities, including misconfigurations at the filesystem and local services level. Whether you administer a web server, a VPN gateway, or a Linux-based firewall, non-least-privilege permissions, poorly designed tasks, exposed management services, and insufficiently verified trust relationships can create unexpected paths for privilege escalation.
The concept of an attack surface is often defined solely by perimeter defenses, but a perimeter strategy is not enough. Conceptually, it makes much more sense to divide the surface into two areas: the external and the internal. The external includes open ports and exposed services, and the internal is where a user who already has local access can cause truly significant damage. A remote exploit isn't necessarily needed to compromise a system; a user with limited access who manages to gain root privileges through misconfigurations is decidedly more worrying.
[...]
Buy Linux Magazine
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
AI Helped Develop a Linux Exploit
A use-after-free race exploit was discovered and exploited on CentOS Stream 9.
-
Yet Another Linux Kernel Vulnerability Discovered
Affecting millions of systems, a kernel flaw discovered by Qualys could allow users to gain root privileges.
-
Ubuntu 26.10 to Include Ubuntu Certified Hardware Check
If you've ever wondered if your laptop or PC is officially certified to run Ubuntu, that curiosity will soon be met.
-
Substantial Update to IPFire Now Available
The lastest version of IPFire features a fundamental change to how the system handles DNS.
-
Gnome Working on Test Center App to Make Testing Easier
It's now possible to test experimental features on the Gnome desktop without worrying that you'll break things.
-
New Vulnerability Discovered in Linux Kernel
Hiding out for nearly 15 years, the Ghostlock vulnerability allows a standard logged-in user to gain root privileges.
-
New Linux Flaw Lets Attackers Escape VMs
A 16-year-old vulnerability allows an attacker to escape a virtual machine, gain access to the host, and execute malicious code.
-
Hannah Montana Linux Is Back!
Developer Noah Cagle decided the world needed the once obscure but beloved Linux distribution and gave it a decidedly pink refresh.
-
System76 Refreshes the Lemur Laptop
If you're looking for a laptop with tons of power and battery, look no further than the latest iteration of the System76 Lemur Pro.
-
More than 43 Million Lines of Code in Linux Kernel 7.2
Using the cloc utility, Michael Larabel of Phoronix discovered that Linux kernel 7.2 has over 43 million lines of code.