Users of the LearnPress WordPress plugin before 4.1.5 can upload an image as a profile avatar after the registration. After this process the user crops and saves the image. Then a "POST" request that contains user supplied name of the image is sent to the server for renaming and cropping of the image. As a result of this request, the name of the user-supplied image is changed with a MD5 value. This process can be conducted only when type of the image is JPG or PNG. An attacker can use this vulnerability in order to rename an arbitrary image file. By doing this, they could destroy the design of the web site.
Kaynak: NIST