Reset the AdminServer Password in WebLogic 11g and 12c:

IF YOU KNOW CURRENT PASSWORD

Start the Admin Server and log into /console.
Go to page: Home > Summary of Security Realms > myrealm > Users and Groups > weblogic. and click on tab Passwords.
Enter the new Password.
Restart the server.
If you get a weblogic.security.SecurityInitializationException error, perform these additional steps on every Managed Server (or eventually the Admin Server, too):

Go to folder <DOMAIN_HOME>/servers/AdminServer/security
Edit the boot.properties file and change the password to the value already entered on the Admin Console. Do this for all the servers in the domain.
Start the Admin Server (Weblogic Server will encrypt the password for you).
Optionally, you can force a Managed Server to connect to the embedded LDAP server on the Administration Server, instead of connecting to the local replicated LDAP server. Follow these steps:

Go to page: Domain > Security > Embedded LDAP page on the Admin Console.
Enable MasterFirst.
Restart the server.


IF YOU DON'T KNOW CURRENT PASSWORD


To reset the password, follow these steps:


Make sure Weblogic Server instance is stopped.

Make a backup of the LDAP folder of the admin server as well as managed servers (you may rename those folders):

<WL_HOME>/user_projects/domains/<DOMAIN_NAME>/servers/<SERVER_NAME>/data/ldap

Set your environment variables by running setDomainEnv.sh (UNIX) or setDomainEnv.cmd (Windows). For example, on UNIX:
. ./setDomainEnv.sh (Notice the space between the dots)


Create a new initialization file for the default authenticator by running the following command that creates a new DefaultAuthenticatorInit.ldift file in the $DOMAIN_HOME/security subdirectory:
java weblogic.security.utils.AdminAccount <ADMIN-USERNAME> <ADMIN-PASSWORD> <DOMAIN_HOME>/security

Note: AdminAccount should be run on the Admin Server, not one of the Managed Servers.


Remove the initialized status file DefaultAuthenticatormyrealmInit.initialized from the <DOMAIN_HOME>/servers/AdminServer/data/ldap/ subdirectory:
cd <WL_HOME>/user_projects/domains/<DOMAINNAME>/servers/AdminServer/data/ldap
rm DefaultAuthenticatormyrealmInit.initialized

NOTE: In some cases, it has been necessary to delete ldap directory for this process to work.

Go to folder <DOMAIN_HOME>/servers/AdminServer/security

Edit the boot.properties file and change the password to the value already used on the previous step. Do this for all the servers in the domain.

Start Weblogic Server (Weblogic Server will encrypt the password for you).


How to Change the WebLogic Server Administrator Password [ID 1082299.1]