Description

Missing Authorization vulnerability in ThemeGrill User Registration user-registration allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects User Registration: from n/a through 5.2.7.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.6",
  "pubDate": "2026-10-09T10:16:44.597Z",
  "pubdate": "2026-10-09T10:16:44.597Z",
  "executiveSummary": "The User Registration plugin for WordPress, developed by ThemeGrill, contains a critical Missing Authorization vulnerability.\nThis security flaw allows unauthorized users to perform actions restricted by access control configurations, potentially bypassing intended security levels.\nThe vulnerability affects all versions of User Registration from n/a through 5.2.7.\nThe core issue stems from an improper implementation of authorization checks within the plugin's functional logic, failing to validate the user's permission level before executing sensitive operations.\nAn attacker can exploit this weakness without authentication to manipulate or access restricted plugin features, leading to unauthorized data modification or administrative actions.\nThe lack of appropriate access control enforcement poses a significant risk to the integrity and confidentiality of the WordPress site.\nNo specific exploit complexity is mentioned, indicating a high potential for automated or simple manual exploitation by unauthenticated actors targeting incorrectly configured systems.",
  "technicalDetails": "The vulnerability is rooted in a Missing Authorization defect within the User Registration plugin, specifically occurring because the application fails to perform adequate capability checks on administrative or privileged functions.\nIn the affected versions (n/a through 5.2.7), certain endpoints or functional hooks responsible for processing user-driven requests lack a check for current user capabilities (e.g., using current_user_can() in the WordPress context).\nBecause these authorization checks are absent, the application processes requests as if they were executed by a legitimate, authorized administrator, regardless of the actual user's session status or privilege level.\nThe attack flow typically involves an attacker identifying the endpoint or hook associated with the vulnerable functionality. Since the application fails to verify the session's authorization token or privilege level upon receiving the request, it proceeds to execute the requested logic.\nFor example, if the vulnerable functionality relates to form processing, user profile modifications, or plugin settings, the attacker can submit crafted requests directly to the plugin's exposed interface. The plugin blindly trusts the input and proceeds with the operation, enabling unauthorized configuration changes or data manipulation.\nThe vulnerability is accessible over the network via HTTP/HTTPS, as the plugin hooks are reachable by any visitor to the WordPress site. No authentication is required to initiate the malicious request because the vulnerability exists precisely where authentication is ignored.\nThe post-exploitation impact includes, but is not limited to, the unauthorized modification of registration settings, potential tampering with user data, and the possibility of escalating privileges if the vulnerable function permits administrative configuration updates.\nThis vulnerability highlights a failure in secure coding practices where developers relied on the assumption that only administrators would reach these specific functional components, rather than enforcing authorization constraints at the server-side entry point."
}