The ora_cleansp errored out with “ORA-01017 invalid username/password” even though correct username and password are supplied (4296573)

While cleaning the environment to start the replication afresh, the ora_cleansp errored out with ORA-01017 invalid username/password. This was despite the correct username and password used in ora_cleansp. The same login credentials allowed connection to SQL*Plus. Here is a sample of the failed session:

$ ./ora_cleansp splex/WX3$674#5DeHw$

Are you sure you want to perform the clean for '/u01/shareplex/vardir' and Port 2100? (N) \c

y

SQL*Plus: Release 11.2.0.4.0 Production on Fri Jun 8 17:52:11 2018

Copyright (c) 1982, 2013, Oracle.  All rights reserved.

ERROR:

ORA-01017: invalid username/password; logon denied

Enter user-name: ERROR:

ORA-01017: invalid username/password; logon denied

Usage: CONN[ECT] [{logon|/|proxy} [AS {SYSDBA|SYSOPER|SYSASM}] [edition=value]]

where <logon> ::= <username>[/<password>][@<connect_identifier>]

      <proxy> ::= <proxyuser>[<username>][/<password>][@<connect_identifier>]

SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus

Unable to log into Oracle.