How to determine DB version / platform-specific release number?

It seems that it should be pretty easy to determine all five digits of a DB release, but in two days of digging, I have not found a good answer yet. Is there a SQL query that will return the all important fifth digit of the RDBMS release number?

Ref: http://docs.oracle.com/cd/E11882_01/server.112/e25494/dba.htm#ADMIN11033

select * from product_component_version; or select * from v$version; present the first four digits, but fifth is always zero.

That fifth digit becomes very critical when selecting patches for a Linux environment.

Env: Linux OEL5, x64; DB 11.2.0.3

Thx.