ASA password recovery

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Nov 13, 2011 9:33 PM
Nov 13th, 2011

Password Recovery Procedure

To recover passwords for the ASA, perform the following steps:

Step 1 Connect to the ASA console port according to the instructions in "Accessing the Command-Line Interface" section.

Step 2 Power off the ASA, and then power it on.

Step 3 After startup, press the Escape key when you are prompted to enter ROMMON mode.

Step 4 To update the configuration register value, enter the following command:

rommon #1> confreg 0x41

Update Config Register (0x41) in NVRAM...

Step 5 To set the ASA to ignore the startup configuration, enter the following command:

rommon #1> confreg

The ASA displays the current configuration register value, and asks whether you want to change it:

Current Configuration Register: 0x00000041
Configuration Summary: 
  boot default image from Flash
  ignore system configuration
Do you wish to change this configuration? y/n [n]: y

Step 6 Record the current configuration register value, so you can restore it later.

Step 7 At the prompt, enter Y to change the value.

The ASA prompts you for new values.

Step 8 Accept the default values for all settings. At the prompt, enter Y.

Step 9 Reload the ASA by entering the following command:

rommon #2> boot
Launching BootLoader...
Boot configuration file contains 1 entry.
Loading disk0:/asa800-226-k8.bin... Booting...Loading...

The ASA loads the default configuration instead of the startup configuration.

Step 10 Access the privileged EXEC mode by entering the following command:

hostname> enable

Step 11 When prompted for the password, press Enter.

The password is blank.

Step 12 Load the startup configuration by entering the following command:

hostname# copy startup-config running-config

Step 13 Access the global configuration mode by entering the following command:

hostname# configure terminal

Step 14 Change the passwords, as required, in the default configuration by entering the following commands:

hostname(config)# password password
hostname(config)# enable password password
hostname(config)# username name password password

Step 15 Load the default configuration by entering the following command:

hostname(config)# no config-register 

The default configuration register value is 0x1.

Step 16 Save the new passwords to the startup configuration by entering the following command:

hostname(config)# copy running-config startup-config

Disabling Password Recovery

You might want to disable password recovery to  ensure that unauthorized users cannot use the password recovery  mechanism to compromise the ASA.

On the ASA, the no service password-recovery command prevents a user from entering ROMMON mode with the configuration intact. When a user enters ROMMON mode, the ASA  prompts the user to erase all Flash file systems. The user cannot enter  ROMMON mode without first performing this erasure. If a user chooses  not to erase the Flash file system, the ASA  reloads. Because password recovery depends on using ROMMON mode and  maintaining the existing configuration, this erasure prevents you from  recovering a password. However, disabling password recovery prevents  unauthorized users from viewing the configuration or inserting different  passwords. In this case, to restore the system to an operating state,  load a new image and a backup configuration file, if available.

Average Rating: 5 (1 ratings)

Comments

steveberglund Wed, 03/26/2014 - 18:37

Small differences, but also successful:

 

Performing Password Recovery for the ASA 5500 Series Adaptive Security Appliance

To recover passwords, perform the following steps:

 

Step 1 Connect to the security appliance console port according to the "Accessing the Command-Line Interface" section on page 2-4.

Step 2 Power off the security appliance, and then power it on.

Step 3 During the startup messages, press the Escape key when prompted to enter ROMMON.

Step 4 To set the security appliance to ignore the startup configuration at reload, enter the following command:

rommon #1> confreg

 

The security appliance displays the current configuration register value, and asks if you want to change the value:

Current Configuration Register: 0x00000011

Configuration Summary:

  boot TFTP image, boot default image from Flash on netboot failure

Do you wish to change this configuration? y/n [n]:

 

Step 5 Record your current configuration register value, so you can restore it later.

Step 6 At the prompt, enter Y to change the value.

The security appliance prompts you for new values.

Step 7 Accept the default values for all settings, except for the "disable system configuration?" value; at that prompt, enter Y.

Step 8 Reload the security appliance by entering the following command:

rommon #2> boot

 

The security appliance loads a default configuration instead of the startup configuration.

Step 9 Enter privileged EXEC mode by entering the following command:

hostname> enable

 

Step 10 When prompted for the password, press Return.

The password is blank.

Step 11 Load the startup configuration by entering the following command:

hostname# copy startup-config running-config

 

Step 12 Enter global configuration mode by entering the following command:

hostname# configure terminal

 

Step 13 Change the passwords in the configuration by entering the following commands, as necessary:

hostname(config)# password password

hostname(config)# enable password password

hostname(config)# username name password password

 

Step 14 Change the configuration register to load the startup configuration at the next reload by entering the following command:

hostname(config)# config-register value

 

Where value is the configuration register value you noted in Step 5 and 0x1 is the default configuration register. For more information about the configuration register, see the Cisco Security Appliance Command Reference.

Step 15 Save the new passwords to the startup configuration by entering the following command:

hostname(config)# copy running-config startup-config

 

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