Shulou(Shulou.com)06/02 Report--

[root@bogon] # useradd-s / sbin/nologin-M mysql

Useradd: cannot open / etc/shadow

[root@bogon ~] # lsattr / etc/shadow

-iMure-/ etc/shadow

The chattr command is locked

Execution

Chattr-I / etc/gshadow

Chattr-I / etc/group

Chattr-I / etc/shadow

Chattr-I / etc/passwd

Give examples to illustrate

1 use the chattr command to prevent a key file in the system from being modified:

# chattr + I / etc/resolv.conf

Then use mv / etc/resolv.conf and other commands to operate on the file, all get the result of Operation not permitted. Vim prompts for a W10: Warning: Changing a readonly file error when editing the file. To modify this file, you need to remove the I attribute: chattr-I / etc/resolv.conf

# lsattr / etc/resolv.conf

The following properties are displayed

-I-/ etc/resolv.conf

2. Let a file only append data to it, but it cannot be deleted. It is applicable to various log files:

# chattr + a / var/log/messages

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