Get the Whitepaper called Exploiting PL/SQL Injection With Only CREATE SESSION Privileges In Oracle 11g.
You can download it from the following link: https://packetstormsecurity.com/files/download/86192/ExploitingPLSQLinOracle11g.pdf
Source: https://packetstormsecurity.com/files/86192/Exploiting-PL-SQL-Injection-With-Only-Create-Session-Privileges-In-Oracle-11g.html