semanage port -l: Displays a list of all ports configured in SELinux and their types.

SELinux and its configured ports

What is SELinux?

SELinux, or Security-Enhanced Linux, is an extension to the Linux kernel that implements a mandatory access control (MAC) system. This means that SELinux controls access to system resources, such as files, directories, processes, and network ports, by applying predefined security policies.

List of ports configured in SELinux

Below is a list of all ports configured in SELinux and their types:

Port number Proto RefCnt Type      Service    Name
0/tcp         tcp    0      sysnetwork unreserved
7/tcp         tcp    0      sysnetwork echo
9/tcp         tcp    0      sysnetwork discard
11/tcp        tcp    0      sysnetwork systat
13/tcp        tcp    0      sysnetwork daytime
17/tcp        tcp    0      sysnetwork qotd
19/tcp        tcp    0      sysnetwork chargen

This list shows the port number, protocol used, reference counter, port type, associated service, and port name. It is important to note that SELinux controls access to these ports according to established security policies.

SELinux Ports and Policies

Why is port configuration important in SELinux?

Port configuration in SELinux is crucial to ensure system security. By controlling access to network ports, SELinux prevents potential network attacks such as intrusions, denial of service, or the installation of malicious software.

How are SELinux policies applied to ports?

SELinux uses security labels to assign policies to network ports. These labels specify what types of access are allowed or denied to a given port. For example, a port used for critical services such as SSH may have more restrictive policies than a port used for less sensitive services.

Recommendations for configuring ports in SELinux

• • Periodically review the ports configured in SELinux to ensure that only the necessary ones are open.

• • Establish specific access policies for each port, taking into account the sensitivity level of the associated services.

• • Limit access to less-used or unnecessary ports to minimize the risk of potential vulnerabilities.

• • Keep security packages and patches up to date to avoid potential port configuration breaches.

In summary, configuring ports in SELinux is a critical aspect of protecting a system's security. By applying appropriate policies and maintaining constant vigilance, a safe and secure environment against potential network threats can be ensured.