$username = "admin";
$password = "password";
$url = "http://www.example.com/";


$postdata = "log=" . $username . "&pwd=" . $password . "&wp-submit=Log%20In&redirect_to=" . $url . "wp-admin/&testcookie=1";
$ch = curl_init();
curl_setopt ($ch, CURLOPT_URL, $url . "wp-login.php");

curl_setopt ($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt ($ch, CURLOPT_USERAGENT, "Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.133 Safari/537.36");
curl_setopt ($ch, CURLOPT_TIMEOUT, 60);
curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, 1);
curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 0);
curl_setopt ($ch, CURLOPT_REFERER, $url . "wp-login.php");
curl_setopt ($ch, CURLOPT_POSTFIELDS, $postdata);
curl_setopt ($ch, CURLOPT_POST, 1);
$result = curl_exec ($ch);

curl_close($ch);
echo $result;

exit;