Brief Introduction to operating system security protection: Linux

Linux, as a symbol of freedom and openness, has received more and more attention from users. However, there are few individual users who actually use Linux, mainly because of its system characteristics and a small number of surrounding software developers, make it only popular in the field of server systems. I will give a brief introduction to its security protection:

1. prohibit access to important files

Linux is not like Windows. It not only publishes source code, but its core program can also be modified as needed, and some key files in the system such as inetd. conf and lilo. can also be modified by remote login users). To protect system security, you can modify its attributes in advance to prevent illegal intrusion and modification.

First, go to the Linux Command interface and enter the command:

# Chmod 600/etc/inetd. conf

Change the file attribute to 600.

Enter the following command:

# Chattr + I/etc/inetd. conf

Ensure that the file owner is root.

In this way, any changes to the file will be prohibited. Only the following commands can be executed:

# Chattr-I/etc/inetd. conf

Root can be modified only after resetting the reset flag.

2. Remote Access prohibited

In Linux, you can use the/etc/hosts. allow and/etc/hosts. deny files to allow and disable remote host access to local services. To do this, go to the Linux Command interface, call up the hosts. deny file, and add the following command:

# Deny access to everyone.

ALL: ALL @ ALL

All services are prohibited from all external hosts unless specified by the hosts. allow file.

In the hosts. allow file, add the following methods to allow access to the Host:

Call out the hosts. allow file and add the following command:

# Just an example:

Http: 192.168.1.8 yanghao.com

This means that machines with IP address 192.168.18 and host name yanghao.com are allowed to access the http service as clients.

This article introduces the system's security protection methods, which cannot be comprehensive. Users who use Windows XP and their "NT core" systems should pay more attention to security issues. When Using XP, it is best to open the built-in firewall to Microsoft and set the firewall to be enabled by default in the new Windows XP ). Users of any system should have certain security knowledge, such as: do not leak their network and system information easily; do not execute unknown programs. A secure system environment is built on your own.