This script can be compiled into a phar file that when called would write a web shell to a shell.txt sub-file, which we can interact with. We can compile it into a phar file and rename it to shell.jpg as follows:
Now, we should have a phar file called shell.jpg. Once we upload it to the web application, we can simply call it with phar:// and provide its URL path, and then specify the phar sub-file with /shell.txt (URL encoded) to get the output of the command we specify with (&cmd=id)
Sometimes there is a strong filter on the file extension when we are uploading files , we can try to bypass that using magic bytes, which means that i will upload the file extension which is required by the server and then i will add the magic byte in the beginning and rest of the file will be my reverse shell and in that case i will get a reverse shell back.
now i will add the pdf magic byte in the beginning and rest of it will be a reverse shell
now find the file where is is uploading and try to get a reverse shell
We can utilize the wrapper to execute PHP code. However, this wrapper isn't enabled by default, so this method may not always work. To do so, we can start by creating a PHP web shell script and zipping it into a zip archive (named shell.jpg), as follows:
