Security researcher David Litchfield has released technical details of a new type of attack that could give a hacker access to an Oracle database.

Called a lateral SQL injection, the attack could be used to gain database administrator privileges on an Oracle server in order to change or delete data or even install software, Litchfield said in an interview on Thursday.

Litchfield first disclosed this type of attack at the Black Hat Washington conference last February, but on Thursday he published a paper with technical details.

In a SQL injection, attackers create specially crafted search terms that trick the database into running SQL commands. Previously, security experts thought that SQL injections would work only if the attacker was inputting character strings into the database, but Litchfield has shown that the attack can work using new types of data, known as date and number data types.

Litchfield's attack targets the Procedural Language/SQL programming language used by Oracle developers.

Oracle did not return so far a comment.