When I publish a Web App, I want to have an images folder that is under the parent automaticlaly set to allow read/write using the Web.config file can I do with without using roles

I have a webapp that allows a user to add and delete images.  The images are uploaded to the server and saved in a folder called "images" one level below the root directory.  I assume that the easiest way to automate the read/write attributes of the images folder is to put it into the web.congif file so that when I publish the web-app the read/write attributes are automatically created.  I understand you can use roles, but is there an easier way to do it.
 
I just want the images folder to have read/write access for all internet users to the app.
How can I do it!
Thanks 
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