Mysql

report/Report.md

@@ -523,4 +523,98 @@ PATH=/usr/lib/sysstat:/usr/sbin:/usr/sbin:/usr/bin:/sbin:/bin
 59 23 * * * root command -v debian-sa1 > /dev/null && debian-sa1 60 2
 ```
 
+### Sudoers
+
+```bash
+root@ls-2024-9:/etc/sudoers.d# cat 90-cloud-init-users
+# Created by cloud-init v. 22.4.2-0ubuntu0~22.04.1 on Thu, 01 Feb 2024 14:23:09 +0000
+
+# User rules for root
+root ALL=(ALL) NOPASSWD:ALL
+```
+
+This rule allows us to run any command as root without password. For any user.
+
+Lets comment it out.
+
+```bash
+visudo -f /etc/sudoers.d/90-cloud-init-users
+```
+
+### Mysql database
+
+Pretty much safe, as the database is not exposed to the internet (visible in `nmap` scan).
+Only local.
+
+```bash
+bind-address            = 127.0.0.1
+mysqlx-bind-address     = 127.0.0.1
+```
+
+BUT.......
+
+when we look at the `ps` output. We can notice:
+
+```bash
+mysql        608  0.8 36.8 1324960 366156 ?      Ssl  07:59   1:05 /usr/sbin/mysqld --skip-grant-tables
+```
+
+- `--skip-grant-tables` This option causes the server to start without using the privilege system at all. 
+This means that anyone can connect to the MySQL server without a password and with all privileges.
+
+
+```bash
+root@ls-2024-9:/etc/systemd/system# systemctl status mysql
+● mysql.service - MySQL Community Server
+     Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: enabled)
+     Active: active (running) since Fri 2024-02-02 07:59:21 UTC; 2h 15min ago
+    Process: 527 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exited, status=0/SUCCESS)
+   Main PID: 608 (mysqld)
+     Status: "Server is operational"
+      Tasks: 38 (limit: 1116)
+     Memory: 362.1M
+        CPU: 1min 7.490s
+     CGroup: /system.slice/mysql.service
+             └─608 /usr/sbin/mysqld --skip-grant-tables
+
+Feb 02 07:59:14 ls-2024-9 systemd[1]: Starting MySQL Community Server...
+Feb 02 07:59:21 ls-2024-9 systemd[1]: Started MySQL Community Server.
+root@ls-2024-9:/etc/systemd/system#
+```
+
+By removing the `--skip-grant-tables` from the `mysql.service` file and restarting the service we can fix this issue.
+
+```bash
+root@ls-2024-9:/etc/systemd/system# cat /lib/systemd/system/mysql.service
+# MySQL systemd service file
+
+[Unit]
+Description=MySQL Community Server
+After=network.target
+
+[Install]
+WantedBy=multi-user.target
+
+[Service]
+Type=notify
+User=mysql
+Group=mysql
+PIDFile=/run/mysqld/mysqld.pid
+PermissionsStartOnly=true
+ExecStartPre=/usr/share/mysql/mysql-systemd-start pre
+ExecStart=/usr/sbin/mysqld --skip-grant-tables
+TimeoutSec=infinity
+Restart=on-failure
+RuntimeDirectory=mysqld
+RuntimeDirectoryMode=755
+LimitNOFILE=10000
+
+# Set enviroment variable MYSQLD_PARENT_PID. This is required for restart.
+Environment=MYSQLD_PARENT_PID=1
+```
+
+```bash
+root@ls-2024-9:/etc/systemd/system# systemctl daemon-reload
+root@ls-2024-9:/etc/systemd/system# systemctl restart mysql.service
+```