PHP教程：你不知道的文件上传漏洞php代码分析

<?php
$uploaddir = 'uploads/'; 
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)){
 echo "File is valid, and was successfully uploaded.\n";
} 
else {
 echo "File uploading failed.\n";
}
?>

<form name="upload" action="upload1.php" method="POST" ENCTYPE="multipart/formdata">
Select the file to upload: <input type="file" name="userfile">
<input type="submit" name="upload" value="upload">
</form>

<?php
if($_FILES['userfile']['type'] != "image/gif") {//获取Http请求头信息中ContentType
 echo "Sorry, we only allow uploading GIF images";
 exit;
}
$uploaddir = 'uploads/';
$uploadfile = $uploaddir.basename($_FILES['userfile']['name']);
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)){
 echo "File is valid, and was successfully uploaded.\n";
} else {
 echo "File uploading failed.\n";
}
?>

<?php
$imageinfo = getimagesize($_FILES['userfile']['tmp_name']);
if($imageinfo['mime'] != 'image/gif' && $imageinfo['mime'] != 'image/jpeg') {
 echo "Sorry, we only accept GIF and JPEG images\n";
 exit;
}
$uploaddir = 'uploads/';
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)){
 echo "File is valid, and was successfully uploaded.\n";
} else {
 echo "File uploading failed.\n";
}
?>

<?php
$blacklist = array(".php", ".phtml", ".php3", ".php4");
foreach ($blacklist as $item) {
if(preg_match("/$item\$/i", $_FILES['userfile']['name'])) {
 echo "We do not allow uploading PHP files\n";
 exit;
}
}
$uploaddir = 'uploads/';
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)){
 echo "File is valid, and was successfully uploaded.\n";
} else {
 echo "File uploading failed.\n";
}
?>

<?php
$uploaddir = 'd:/uploads/';
$uploadfile = $uploaddir . basename($_FILES['userfile']['name']);
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) {
　　echo "File is valid, and was successfully uploaded.\n";
} else {
　　echo "File uploading failed.\n";
}
?>

<?php
$uploaddir = 'd:/uploads/';
$name = $_GET['name'];
readfile($uploaddir.$name);
?>

<?php
require_once 'DB.php';
$uploaddir = 'D:/uploads/'; 
$uploadfile = tempnam($uploaddir, "upload_");
if (move_uploaded_file($_FILES['userfile']['tmp_name'], $uploadfile)) {
　　$db =& DB::connect("mysql://username:password@localhost/database");
　　if(PEAR::isError($db)) {
　　　　unlink($uploadfile);
　　　　die "Error connecting to the database";
　　}
　　$res = $db->query("INSERT INTO uploads SET name=?, original_name=?,mime_type=?",
　　　　　　array(basename($uploadfile,basename($_FILES['userfile']['name']),$_FILES['userfile']['type']));
　　if(PEAR::isError($res)) {
　　　　unlink($uploadfile);
　　　　die "Error saving data to the database. The file was not uploaded";
　　}
　　$id = $db->getOne('SELECT LAST_INSERT_ID() FROM uploads');
　　echo "File is valid, and was successfully uploaded. You can view it <a href=\"view.php?id=$id\">here</a>\n";
} else {
　　echo "File uploading failed.\n";
}
?>

<?php
require_once 'DB.php';
$uploaddir = 'D:/uploads/';
$id = $_GET['id'];
if(!is_numeric($id)) {
　　die("File id must be numeric");
}
$db =& DB::connect("mysql://root@localhost/db");
if(PEAR::isError($db)) {
　　die("Error connecting to the database");
}
$file = $db->getRow('SELECT name, mime_type FROM uploads WHERE id=?',array($id), DB_FETCHMODE_ASSOC);
if(PEAR::isError($file)) {
　　die("Error fetching data from the database");
}
if(is_null($file) || count($file)==0) {
　　die("File not found");
}
header("Content-Type: " . $file['mime_type']);
readfile($uploaddir.$file['name']);
?>