Hi,

I'm making a online posting ad web application and it will require the end user to upload a image of his/her item. I'm working on the preview post function as of now and would like to know if the way I'm doing it leaves any major security risks.

Once a user posts his info and attaches his image to be uploaded, it will lead to a preview page that will view this image from a tmp folder (not outside my web directory). If he clicks "Choose a different image" then it will lead to the previous page and at the same time delete that image in the tmp folder. If he clicks submit final, then it will store the posting info and move the image in the tmp folder to the folder all images will be stored in.

For the upload code, I have a limit set and I check the file extension along with the MIME type. I only allow .gif, .jpeg, and .tiff.

Some of the possible security risks that come to mind is if a user decides to keep uploading to the tmp folder and not doing anything after, therefore it will leave that image uploaded inside the tmp folder. Someone may make a script to auto fill the post and upload tons of images inside my directory. To counter this I can probably do a post verification, but don't really want to if not necessary (as in other methods to carry out my function that will not need to do this).

Thanks for taking your time to read this.
tanger

In reply to Preview uploaded image by tanger

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