<?php

$data = array("attr1", "attr2", "attr3", "attr4", "attr5");
$required = array("attr2", "attr5");
$data2 = array("attr1", "attr3", "attr4", "attr5");

function validate_required ($data, $required) {
    $c = 2;

    $inBoth = array_intersect($data, $required);
    if (count($inBoth) !== $c) {
        throw new \Exception('O elemento {elemento} não possui todos os atributos obrigatórios');
    }
    return true;
}

var_dump(validate_required($data, $required));
var_dump(validate_required($data2, $required));