Is there any way to identify which built-in PHP function is used in some given script only by sending a request and receiving a response from the remote server?

To keep it simple we might assume that it is very simple PHP script which contains only one PHP function. I understand that it seems rather impossible to accomplish that since we might have an overlap of different effects which might delay the request/response time (network, server itself, ..) and make it impossible to find such a correlation.

But maybe it is anyhow possible to create an extremly limited case where it is still possible to reliably identify which PHP functions are used in a given script. It must not be necessarily a PHP scripting language.

I'm searching for different ways to fingerprint a PHP version running on a server.


1 Answer 1


That's not possible I think. The response may change because a lot of factors: server hardware and resources, server load, connection status, etc.

I think is not possible even in the extremely case of reproduce exactly the same script in same hardware. You'll never get the same miliseconds of response. Maybe even micro electric variations can affect.

  • Agree. Then this direction of fingerprinting PHP version seems to be a dead end. Commented May 16, 2017 at 21:57

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .