Practical skills for preventing hackers in Linux

Practical tips for preventing hackers in Linux-General Linux technology-Linux programming and kernel information. For more information, see the following. Practical skills for preventing hackers in Linux
Linux is a multi-user system. Once a root user is obtained, he can do whatever he wants on your system. because a single user has full control permissions on the system, if the operation is improper or is entered by others, the consequences will be unimaginable. There are several considerations to prevent the entry of a single user.

1. protect the/etc/inittab file. if you change 3 in id: 3: initdefault to 1, you can directly access the single-user mode at each startup. For the/etc/inittab file, enter as root and set the attribute to another user through chown700/etc/inittab.

2. if you are using lilo for boot, you may use linuxconf or directly modify lilo. Conf sets the waiting time for input during boot to 0 or the shortest time. In this case, if you enter the single-user mode, you can use a floppy disk for boot.

3. if GRUB is used for boot, the simplest method is to use the GRUB password to protect the startup options.

4. in order to prevent remote damage and restart the system, in addition to effectively managing the ROOT password and files in the/etc directory, the CMOS password should also be set, in this way, even if the system is changed to a single user mode, the computer cannot be started directly.