What is the proper response when a professor teaches a side topic related to the course but the information is wrong? I've been a software developer for about 10 years or so and am familiar with various security related concepts (SQL injection, server-client validations, man-in-the-middle attacks, etc.)

I'm upgrading from a college diploma and found myself sitting in an "Enterprise Application Development" class learning about SQL.

The core content is very basic and normally doesn't cover security, but the teacher decides to talk about it. He advised students to use mixed cased table names as "security" so that it is harder to guess. This is known as "Security Through Obscurity" and is one of the least effective form of security (it is treated as insecure). Security is talked about throughout the class and they're all forms of the same thing and extremely dangerous since it is completely ineffective.

As a professional that knows better, if he was an employee I would've had to sit him down and have a thorough talk, and probably advise some security training. 

What can do I do as a student? Since the other students are probably clueless 
and security is not even one of the program's topic, there is no foreseeable chance for correct learning and they will probably end up doing this in the future, possibly jeopardizing their own career, the company, and all the data they work with.
If the teacher is not a reasonable person, and some are not, you should keep your head down and hope that your fellow students will get some real security training, at least on the job, before making decisions in this area.

If the teacher is reasonable, select a very small number of references on the topic, preferably including peer-reviewed papers. Look for an opportunity to talk with the teacher privately, definitely not in class and preferably without any of your fellow students nearby.

Explain that you have had to learn about some security issues because of your jobs over the last 10 years, and that you have more up-to-date information than is being presented in class. (Yes, I know something of the history of security-through-obscurity, but we are being tactful here). Offer your references. How you play it from there on will have to depend on how receptive the teacher is, and how helpful you are willing to be.