I'm participating in a CTF, and I need to upload a file that, once loaded, executes a PHP script—any PHP script. The challenge is that the website only accepts file extensions like .jpg, .png, .gif, and .bmp.
The given clue is "unknown extension."
Thanks.
I attempted naming it php.php.jpg, which allowed the upload, but unfortunately, the PHP script doesn't run after loading. I also experimented with exiftool, but encountered the same issue.
I also tried file.php%00.jpg, but it didn't work.