If you do not configure security, you must be aware of the following vulnerabilities.

• Network JDBC: Network JDBC connections expose sensitive operations to use by persons who may not have account privileges on the database machine.
• Cleartext traffic: By default, network traffic travels in cleartext.
• Unbounded growth: Tables can grow arbitrarily large.
• CPU hogging: Unbounded CPU cycles can be consumed by connection attempts, SQL queries, and user code running in the database.
• Superusers: By default, all users enjoy extensive powers to read and write in all databases.
• Launch privileges: procedural code executes with the operating system privileges of the account that launched the virtual machine. This includes system-supplied procedures as well as custom, user-coded procedures.
• User code: Arbitrary user code can execute in the virtual machine by means of user-coded functions and procedures.
• Open source: 's code itself is publicly visible as part of the open source project. This means that an attacker can write subtle malware after studying the code and file formats. Note that while closed source code enjoys the advantage of "security by obscurity", openness can confer other, countervailing security advantages.