REM Sneak in as another user if you have the alter user privilege. This script creates reset.sql which can be executed to reset the password to the old one.

spool resetpass.sql
select
'ALTER USER &&1 IDENTIFIED BY VALUES '
||

||Password||

||';' from DBA_USERS
where Username = UPPER('&&1');
spool off;
alter user &&1 identified by sneaking;
connect &&1/sneaking
/