I can understand that it could be an O.S. security issues. But I don't believe it is to be blame with the SAMBA software. SAMBA only enable users within a network to a access your UNIX box who has security privs from a Windows computers and that's it.
It could be on the process of installing SAMBA some ORACLE related files were unintensionally altered by the unix admin. That's the only reason I can think of.