Follow this step-by-step guide to install PostgreSQL, load data, connect to a database, and execute SQL queries including table joins PostgreSQL is an open-source, object-relational (also called ...

Furthermore, psql has a feature called meta-commands that allows the execution of shell commands via the \! meta-command. This capability transforms the SQL injection into OS command code execution.

The SQL injection allowed the attacker to freely use psql, an interactive interface that comes with PostgreSQL, and to not only access the database but also enter arbitrary system commands via psql.