Setuid

Finding setuid binaries on Linux and BSD

To perform a basic audit of the binaries on your system, we can search for setuid binaries. Finding these setuid binaries is easy with the find command.

Summary of Finding setuid binaries on Linux and BSD

Why setuid? Binaries with the setuid bit enabled, are being executed as if they were running under the context of the root user. This enables normal (non-privileged) users to use special privileges, like opening sockets. While this seems unnecessary for a normal user, it is actually needed for simple commands like ping. Finding files with setuid bit To discover all files with the setuid bit, we can use the find command.

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Linux capabilities 101

Introduction guide and tutorial about the inner workings of Linux capabilities and how these capabilities are applied when running Linux processes.

Summary of Linux capabilities 101

Security of Linux systems and applications can be greatly improved by using hardening measures. One of these measures is called Linux capabilities. Capabilities are supported by the kernel for some while now. Using capabilities we can strengthen applications and containers. Unfortunately, this powerful tool is still underutilized. Time to change that! This article helps to understand and apply them. What are Linux capabilities? Normally the root user (or any ID with UID of 0) gets a special treatment when running processes.

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Linux Capabilities: Hardening Linux binaries by removing setuid

Setuid binaries may be a risk for the system. We will investigate how to remove the setuid bit and use Linux capabilities instead, to reduce the risks.

Summary of Linux Capabilities: Hardening Linux binaries by removing setuid

Hardening Linux binaries by removing setuid Normally Unix based systems use two kind of processes: privileged and unprivileged. The first category is usually used for administrative purposes, like starting and stopping other processes, tuning the kernel and opening sockets. Root permissions The command ping is a great example why even small programs needs root permissions. In a first glance you might consider this tool to be simple: send a package to a host and see if it responds.

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