mysql用户可免密码登录问题处理解决-Toy模板网

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现象描述

任意用户可登录MySQL数据库。如下面操作。会发现，此时登录后无法查看到正常的全部数据库，只能看到系统默认的测试数据库test和信息库infomation_schema。

else@linux-ctc7:~> mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 5.1.73-community MySQL Community Server (GPL)

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| test               |
+--------------------+
2 rows in set (0.00 sec)

分析

正常登录该数据库，查看用户表，第四列里面，host为localhost，用户为空，密码为空。导致在本地登陆的时候除了root的账户外，其他账号不需要密码即可登陆，并且影响host为%的用户登陆。

else@linux-ctc7:~> mysql -uroot -pmysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 12
Server version: 5.1.73-community MySQL Community Server (GPL)

Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> select host,user,password from user;
+------------+------+-------------------------------------------+
| host       | user | password                                  |
+------------+------+-------------------------------------------+
| %          | root | *E74858DB86EBA20BC33D0AECAE8A8108C56B17FA |
| linux-ctc7 | root |                                           |
| 127.0.0.1  | root |                                           |
| localhost  |      |                                           |
| linux-ctc7 |      |                                           |
+------------+------+-------------------------------------------+
5 rows in set (0.00 sec)

mysql>

解决

删除空用户。然后重启数据库。不重启数据库不生效。文章来源地址https://www.toymoban.com/news/detail-637494.html

mysql> select host,user from user;
+------------+------+
| host       | user |
+------------+------+
| %          | root |
| 127.0.0.1  | root |
| linux-ctc7 |      |
| linux-ctc7 | root |
| localhost  |      |
| localhost  | test |
+------------+------+
6 rows in set (0.00 sec)
mysql> delete from user where host='localhost' and user='';
Query OK, 1 row affected (0.00 sec)
mysql> delete from user where host='linux-ctc7' and user='';
Query OK, 1 row affected (0.00 sec)

//不重启数据库不生效。重启后生效。
else@linux-ctc7:~> mysql -u else             ---重启数据库前仍可登录
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 23
Server version: 5.1.73-community MySQL Community Server (GPL)
Copyright (c) 2000, 2013, Oracle and/o its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>
linux-ctc7:/etc/init.d # ./mysql stop
Shutting down MySQL..                                                 done
linux-ctc7:/etc/init.d # ps -ef|grep mysql
root      5561  5490  0 09:03 pts/1    00:00:00 grep mysql
linux-ctc7:/etc/init.d # ./mysql start
Starting MySQL.                                                       done
linux-ctc7:/etc/init.d # mysql       ---重启数据库后，root用户无法直接连接。
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
else@linux-ctc7:~> mysql -u else     ---重启数据库后，普通用户无法直接连接。
ERROR 1045 (28000): Access denied for user 'else'@'localhost' (using password: NO)