It seems that with 4.3.0 branch something is missing in the libs. A user reported connection problems with his Oracle DB after the upgrade. I can't find anything related to Oracle in 4.3.2 lib folder. Although there is nothing also in 4.2.3 version's lib folder. This user had separate oracle connector jar in his old installation and then copied it to new installation and it fixed the issue. It might be that his DB version is old and not supported by current connectors.
Note; this is largely a documentation issue. The Oracle drivers cannot be maintained within a Maven repository due to their licensing restrictions, so instead they have to be downloaded manually from Oracle's web site.