CVE-2026-78284 in MasterStudy Plugin
Summary
by MITRE • 08/25/2026
Unauthenticated Arbitrary File Deletion in MasterStudy LMS <= 3.7.42 versions.
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Analysis
by VulDB Data Team • 08/25/2026
The vulnerability identified as an unauthenticated arbitrary file deletion flaw within MasterStudy Learning Management System versions prior to or equal to 3.7.42 represents a critical security deficiency that allows attackers to remove files from the server hosting the application without requiring valid credentials. This type of vulnerability typically stems from insufficient input validation and inadequate authorization checks in functions responsible for handling user-supplied data related to file operations. In many cases, such flaws arise when developers rely on client-side controls or assume that certain administrative endpoints are only accessible by authenticated users, failing to enforce server-side access control mechanisms properly. The absence of these safeguards enables an unauthenticated actor to craft specific HTTP requests targeting internal APIs or script handlers that process file paths directly from request parameters without sanitization or verification against a whitelist of allowed directories and files.
From a technical perspective, the exploitation mechanism generally involves manipulating query strings or POST data to specify arbitrary file paths on the underlying operating system. By leveraging directory traversal sequences such as dot-dot-slash characters, an attacker can navigate outside the intended web root or application-specific storage areas to target sensitive configuration files, database dumps, backup archives, or core script files essential for the platform's operation. This capability is particularly dangerous because it bypasses standard authentication gates that would normally restrict access to administrative functions involving file management. The vulnerability aligns closely with CWE-22 Improper Limitation of a Pathname to a Restricted Directory and CWE-650 Trusting Own Data, as the application fails to validate whether the requested resource is within an allowed scope or if the user has legitimate permission to perform deletion actions on that specific asset.
The operational impact of this vulnerability can be severe, ranging from service disruption to complete system compromise depending on which files are targeted. If critical configuration files such as wp-config.php in WordPress-based installations or database connection scripts are deleted, the learning management system may become entirely inaccessible, leading to significant downtime and loss of availability for students and instructors relying on the platform for educational activities. Furthermore, if backup files containing sensitive student data, personal identifiable information, or financial records are removed, it could result in irreversible data loss and potential regulatory violations under frameworks like GDPR or FERPA. In more advanced attack scenarios, an attacker might delete security-related logs to cover their tracks after performing other malicious actions, thereby hindering incident response efforts and forensic analysis capabilities for system administrators.
This vulnerability is also relevant to the MITRE ATT&CK framework, specifically mapping to techniques involving file deletion as a method of impact or defense evasion. Attackers may utilize this flaw not only to cause immediate damage but also to facilitate further exploitation by removing security controls that monitor malicious activity. The lack of authentication requirement makes it particularly attractive for automated scanning tools and opportunistic attackers who seek quick wins against poorly secured installations. It highlights the importance of implementing robust access control lists on all endpoints, regardless of their perceived sensitivity or intended audience, ensuring that even public-facing pages enforce strict permission checks before executing any destructive operations.
To mitigate this vulnerability, administrators should immediately upgrade MasterStudy LMS to version 3.7.42 or later where these issues have been addressed by the developers through improved input validation and stricter authorization protocols. Until an update can be applied, temporary mitigations include restricting access to administrative interfaces via IP whitelisting if feasible, implementing Web Application Firewall rules that detect and block common directory traversal patterns in file-related parameters, and ensuring that web server configurations prevent direct execution or deletion of sensitive files through proper permissions settings on the hosting environment. Regular security audits and penetration testing should be conducted to identify similar weaknesses across other plugins and themes integrated with the LMS platform, as these components often share codebases and may exhibit comparable flaws if not properly secured against untrusted input.