Description

Subscriber Broken Access Control in MasterStudy LMS <= 3.7.41 versions.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-18T15:17:07.673Z",
  "pubdate": "2026-08-18T15:17:07.673Z",
  "executiveSummary": "A broken access control vulnerability exists in the MasterStudy LMS product affecting versions 3.7.41 and below. This security flaw allows malicious actors authenticated with minimal privileges, specifically the Subscriber role, to perform unauthorized actions restricted to higher-privileged users.\nThe primary impact of this vulnerability involves the potential compromise of application integrity and data confidentiality, as low-privileged users can bypass intended security boundaries within the LMS platform. The risk implications are severe for educational institutions and organizations utilizing the affected software, as unauthorized function execution can lead to administrative takeover, unauthorized course modification, or sensitive data exposure.\nExploitation of this vulnerability requires the attacker to possess a valid Subscriber-level account on the target system to interact with vulnerable endpoints. No complex social engineering or advanced exploitation frameworks are strictly required, provided the attacker can issue crafted requests directly to the affected functions. The vulnerability highlights a failure in proper authorization checks and capability verification within the backend request-handling logic of MasterStudy LMS <= 3.7.41 versions.",
  "technicalDetails": "The root cause of this vulnerability is the absence of robust access control checks and role-based authorization enforcement within specific request handlers of the MasterStudy LMS <= 3.7.41 versions. When application endpoints process functional requests, the underlying codebase fails to adequately validate whether the requesting user context, authenticated merely as a Subscriber, possesses the necessary capabilities or administrative privileges required to execute the requested actions.\nThe vulnerable components reside within the backend routing and controller logic of the MasterStudy LMS plugin, where sensitive functions lack strict capability checks such as current_user_can() validations or nonces verification. An attacker authenticated with a standard Subscriber account can leverage this flaw by identifying exposed AJAX actions, REST API endpoints, or direct function calls intended exclusively for administrators, instructors, or higher-privileged roles.\nThe attack flow proceeds as follows: First, the attacker authenticates to the target WordPress instance with a standard Subscriber account. Second, the attacker formulates an HTTP request targeted at the unprotected or improperly authorized MasterStudy LMS endpoint, injecting parameters corresponding to the restricted action they wish to perform. Third, because the application processes the request without verifying the user's role against the required privilege level, the server executes the privileged function on behalf of the low-privileged user. Finally, the attacker receives a response confirming the execution of the unauthorized action, achieving privilege escalation within the context of the LMS functionality.\nThe exploitation method relies on direct interaction with the exposed application endpoints, bypassing the user interface constraints that typically hide unauthorized features from standard Subscribers. Since the network exposure includes any web interface accessible to authenticated users, the attack vector is readily exploitable over standard HTTP/HTTPS protocols. The post-exploitation impact depends heavily on the specific functions targeted, potentially allowing low-privileged users to modify site settings, alter course structures, access restricted learning materials, or perform other administrative operations within the MasterStudy LMS environment."
}