Microsoft Internet Explorer (and windows too) would be an example of a closed source script. As we all know, there have been security issues. Firefox would be an example of an open source script. As we all know, there have been fewer security issues.

Both are vulnerable, and the most important thing to do is look at the history of the script you are considering. In phpLD, the data is sanitized on form field submissions, so most mods are pretty safe. It also depends on what you call a mod. Many of the so called mods are simply changes to the smarty templates, and are not actual PHP code changes, in which case there is virtually no additional risk.

I might also note that when we spot issues with phpLD mods (not just security issues) we often help mod developers improve their mods. This also sometimes works in reverse.

Educating yourself is the best thing you can do, as well as making sure you are working with good people.

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As you guided I read on sanitizing and see it very important to be safer than sorrier but may be it is difficult to check on modules created by outside peoples. This is being my main worry about going with opensource code because I have to show care with my money and damage is no good to me if I do not know who I will be dealing with.

Your advice is good and I am thanking you for this, I am ponder to buy either product directory script or if possible a established one to save me work on setting it up as I see it so difficult a problem getting pagerank anymore. I will be educating plenty to do right thing.

Yes, it is right to study carefully first. And if you do decide to use programming by someone else (such as for a mod), make sure you work with someone that has a good reputation.

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That is very good advice thankyou dduval. I am lucky to be able to code for my own but wanting to avoid this to stay focussing on objective of success.