Setting the creation date of each file in a folder to mach its own “last modifictaion” date automatically

I got a folder of about 1000 pictures and videos. The creation date of the files is incorrect, but the “last modified” time stamp is correct. I want to set the creation date of each of the files in the folder to mach its own “last modifictaion” date, automatically using CMD or any program that is capable of this.