How can outdated PHP functions like $HTTP_GET_VARS impact the security of a website?

Using outdated PHP functions like $HTTP_GET_VARS can impact the security of a website because these functions are deprecated and no longer supported in newer versions of PHP. This can leave the website vulnerable to security risks such as injection attacks. To solve this issue, it is recommended to use the superglobal $_GET array instead to access GET variables securely.

// Use the $_GET superglobal array to access GET variables securely
$var = $_GET['variable_name'];