Monitoring and Restricting root Access (Tasks)

By default, the root role is assigned to the initial user, and cannot directly log in to the local system or remotely log in to any Oracle Solaris system.

How to Monitor Who Is Using the su Command

The sulog file lists every use of the switch user (su) command, not only the su attempts that are used to switch from user to root.

Before You Begin

You must assume the root role. For more information, see How to Use Your Assigned Administrative Rights.

• Monitor the contents of the /var/adm/sulog file on a regular basis.

  # more /var/adm/sulog
  SU 12/20 16:26 + pts/0 stacey-root
  SU 12/21 10:59 + pts/0 stacey-root
  SU 01/12 11:11 + pts/0 root-rimmer
  SU 01/12 14:56 + pts/0 jdoe-root
  SU 01/12 14:57 + pts/0 jdoe-root

  The entries display the following information:

  • The date and time that the command was entered.

  • If the attempt was successful. A plus sign (+) indicates a successful attempt. A minus sign (-) indicates an unsuccessful attempt.

  • The port from which the command was issued.

  • The name of the user and the name of the switched identity.

  The su logging in this file is enabled by default through the following entry in the /etc/default/su file:

  SULOG=/var/adm/sulog

Troubleshooting

Entries that include ??? indicate that the controlling terminal for the su command cannot be identified. Typically, system invocations of the su command before the desktop appears include ???, as in SU 10/10 08:08 + ??? root-root. After the user starts a desktop session, the ttynam command returns the value of the controlling terminal to the sulog: SU 10/10 10:10 + pts/3 jdoe-root.

Entries similar to the following can indicate that the su command was not invoked on the command line: SU 10/10 10:20 + ??? root-oracle. A Trusted Extensions user might have switched to the oracle role by using a GUI.

How to Restrict and Monitor root Logins

This method immediately detects root attempts to access the local system.

Before You Begin

You must assume the root role. For more information, see How to Use Your Assigned Administrative Rights.

1. View the CONSOLE entry in the /etc/default/login file.

   CONSOLE=/dev/console

   By default, the console device is set to /dev/console. With this setting, root can log in to the console. root cannot log in remotely.

2. Verify that root cannot log in remotely.

   From a remote system, try to log in as root.

   mach2 % ssh -l root mach1
   Password: <Type root password of mach1>
   Password: 
   Password: 
   Permission denied (gssapi-keyex,gssapi-with-mic,publickey,keyboard-interactive).

   In the default configuration, root is a role, and roles cannot log in. Also, in the default configuration the ssh protocol prevents root user login.

3. Monitor attempts to become root.

   By default, attempts to become root are printed to the console by the SYSLOG utility.

   1. Open a terminal console on your desktop.
   2. In another window, use the su command to become root.

      % su -
      Password: <Type root password>
      #

      A message is printed on the terminal console.

      Sep 7 13:22:57 mach1 su: 'su root' succeeded for jdoe on /dev/pts/6

Example 3-5 Logging root Access Attempts

In this example, root attempts are not being logged by SYSLOG. Therefore, the administrator is logging those attempts by removing the comment from the #CONSOLE=/dev/console entry in the /etc/default/su file.

# CONSOLE determines whether attempts to su to root should be logged
# to the named device
#
CONSOLE=/dev/console

When a user attempts to become root, the attempt is printed on the terminal console.

SU 09/07 16:38 + pts/8 jdoe-root

Troubleshooting

To become root from a remote system when the /etc/default/login file contains the default CONSOLE entry, users must first log in with their user name. After logging in with their user name, users then can use the su command to become root.

If the console displays an entry similar to Last login: Wed Sep 7 15:13:11 2011 from mach2, then the system is configured to permit remote root logins. To prevent remote root access, change the #CONSOLE=/dev/console entry to CONSOLE=/dev/console in the /etc/default/login file. To return the ssh protocol to the default, see the sshd_config(4) man page.