The following information will help you with the installation of an Oracle Critical Patch Update (CPU).
Vulnerability Patching
# lsnrctl stop
SQL> conn sys as sysdba;
SQL> shutdown
Confirm the ORACLE_HOME
environment variable is pointing to your Database Home eg: D:\oracle\product\12.2.0.1\db_1\
Windows: echo %ORACLE_HOME%
Linux: echo $ORACLE_HOME
Go to the directory where the patch is located and then run the OPatch utility by entering the following commands:
unzip p28265827_112040_MSWIN-x86-64.zip cd 28265827 opatch apply