A post about hacking the Linux operating system using user administration. We will be discussing some Linux hacks with which we can play around user security.
Blocking any regular user from logging in.
You can perform any of the below Linux hacks so that a specific user will not be able to log in.
1. Replacing ‘x’ with ‘*’ in the second area / etc / passwd.
[[email protected] ~]# cat /etc/passwd|grep -i test testuser:*:500:500::/home/testuser:/bin/bash [[email protected] ~]#
2. Change the default shell of the user / sbin / nologin using the 7th field from / etc / passwd or using the command.
[[email protected] ~]# chsh testuser Changing shell for testuser. New shell [/bin/bash]: /sbin/nologin Shell changed. [[email protected] ~]#
3. Changing the 8th field / etc / shadow to 0.
[[email protected] ~]# cat /etc/shadow|grep test testuser:$6$gFZOkJ.9$AhMOsn/R6G1PQBXcN.KesHlCVa5ylALdqjcZuWSsL6p24YGq5pnciT12fhysewIJWUwc6uoafaIS9KkieTjGc0:17166:0:99999:7::0: [[email protected] ~]#
4. Commenting out the line corresponding to the user in / etc / passwd.
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[[email protected] ~]# cat /etc/passwd|grep -i test #testuser:x:500:500::/home/testuser:/bin/bash [[email protected] ~]#
With the four described methods, we can perform a Linux hack on any specific user, now allows Linux to be executed to hack the Linux user base.
5. In order to block all regular users of the system from logging into the system, it is necessary to create a file ‘nologin’ in / etc. If there is no text contained in the file, no messages will be sent to users when they log in with a username and password, and the prompt will return to login.
Now, to perform a Linux hack for the root user, use one of the following:
6. Change the 8th field / etc / shadow to 0 for the root entry. (Which can only be done by the root, since it is the only one who can read the file.
7. You can also comment out the lines below corresponding to the device drivers in the / etc / securetty file, ie. commenting on the following fields:
tty1 tty2 tty3 tty4 tty5 tty6 tty7 tty8 tty9 tty10 tty11
These are 7 ways to hack a Linux system. You can try to do the same.