【SWPUCTF 2022 新生赛】funny_php

Ting included in Web · 2024做题

2024-10-31 About 100 words One minute

Contents

[SWPUCTF 2022 新生赛]funny_php

思路

源码

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 <?php
error_reporting(0);
header("Content-Type: text/html;charset=utf-8");
highlight_file(__FILE__);
include('flag.php');
if (isset($_GET['num'])) {
    $num = $_GET['num'];
    if ($num != '12345') {
        if (intval($num) == '12345') {
            echo $FLAG;
        }
    } else {
        echo "这为何相等又不相等";
    }
}

三个点
- $num != '12345'这里是弱比较
- intval()截断。当向intval()传入的参数，不是int时，会返回1

Payload

末尾随便放个非int

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?num=12345/
?num=12345a

总结

弱比较
数组绕过