Connect from Oracle 10 Client to Oracle19 Server giving "ORA-01017: invalid username/password; logon denied"

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Issue

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When connecting from Oracle 10 to Oracle 19, it is giving an error:
ORA-01017: invalid username/password; logon denied

But, when connecting with same credentials on the oracle 19 server, the connection is OK

-??!!

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How to fix

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Need to check value for PASSWORD_VERSIONS for the user in question

SELECT username, account_status, password_versions 

  FROM DBA_USERS 

 WHERE username = 'DBA_USER';

USERNAME          ACCOUNT_STATUS    PASSWORD_VERSIONS 
---------------   --------------    -----------------
DBA_USER          OPEN              11G 12C 

Connection from Oracle 10 Client would not be able to login.

Need to make password_versions compatible with 10g.

To fix:  edit sqlnet.ora:

SQLNET.ALLOWED_LOGON_VERSION = 8

SQLNET.ALLOWED_LOGON_VERSION_SERVER=8 

SQLNET.ALLOWED_LOGON_VERSION_CLIENT = 8

Then restart Listener.

Then reset/change the password for the user.

Now, the PASSWORD_VERSIONS allows connection from oracle 10.

ALTER USER DBA_USER IDENTIFIED BY NEW_USER_PASS;

SELECT username, account_status, password_versions 

  FROM DBA_USERS 

 WHERE username = 'DBA_USER';

USERNAME          ACCOUNT_STATUS    PASSWORD_VERSIONS 
---------------   --------------    -----------------
DBA_USER          OPEN              10G 11G 12C

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Additional Info

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A known issue

Due to security changes in authentication, starting from Oracle 12, it might be that users from Oracle Client with older version cannot login to newer Oracle Server.

To allow that:

Check 1 : SEC_CASE_SENSITIVE_LOGON = FALSE

Check 2:  PASSWORD_VERSIONS should be that of the Client