CVE-2026-19093 in Tutor LMS Plugin
Summary
by MITRE • 08/22/2026
The Tutor LMS WordPress plugin before 4.0.6 does not validate a stored file path before using it to stream media, allowing users with the instructor role to read arbitrary files on the server, including files outside the web root.
The readable files include the WordPress configuration file, which exposes the database credentials and the authentication keys and salts, so authentication cookies can be forged.
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Analysis
by VulDB Data Team • 08/22/2026
The vulnerability identified in Tutor LMS versions prior to 4.0.6 represents a critical server-side path traversal flaw that stems from insufficient input validation regarding stored file paths. The core technical issue lies in how the plugin handles media streaming operations, specifically when an instructor attempts to access or stream course materials. Instead of strictly validating whether the requested file path resides within the expected directory structure or adhering to safe character sets, the application directly incorporates user-supplied data into filesystem functions without adequate sanitization. This lack of validation allows a malicious actor with the instructor role to manipulate the file path parameter, effectively bypassing intended access controls and directing the server to read arbitrary files from the underlying operating system.
The operational impact of this vulnerability is severe due to the high privilege level required for exploitation versus the sensitivity of the data exposed. An attacker possessing only an instructor account can exploit this flaw to perform unauthorized local file inclusion or reading operations. By constructing a malicious request that utilizes directory traversal sequences, such as dot-dot-slash notation, the attacker can navigate up through the web root and access sensitive configuration files located in parent directories. This capability effectively neutralizes many standard security boundaries because it allows read access to any file on the server for which the web server process has permissions, regardless of whether that file is publicly accessible via HTTP or hidden from direct browser requests.
The most critical consequence of this exploitation vector is the potential compromise of the entire WordPress installation through the exposure of configuration files. Specifically, attackers can target the wp-config.php file, which contains database credentials, authentication keys, and salts. The disclosure of these secrets allows for sophisticated attacks beyond simple data theft. With access to the database credentials, an attacker could potentially extract all user data from the backend database directly if other defenses are weak. More immediately, knowledge of the authentication keys and salts enables the forging of secure cookies. This means an attacker can impersonate any existing user on the site, including administrators, without needing valid login credentials or performing brute-force attacks against passwords.
From a classification perspective, this vulnerability aligns with CWE-22: Improper Limitation of a Pathname to a Restricted Directory and CWE-94: Improper Control of Generation of Code (Code Injection) in the context of file inclusion mechanisms. In terms of adversary behavior, it maps to ATT&CK technique T1083: File and Directory Discovery, as well as T1552.004: Unsecured Credentials, specifically involving the retrieval of configuration files containing sensitive information. The exploitation path demonstrates how a seemingly minor input validation error in media handling can escalate into full system compromise by leveraging existing high-privilege roles to access foundational security artifacts.
Mitigation strategies must prioritize immediate patching and defensive coding practices. Administrators running affected versions should upgrade Tutor LMS to version 4.0.6 or later, where the developers have implemented proper validation for file paths used in media streaming functions. In addition to updating software, organizations should enforce strict least-privilege principles by ensuring that instructor accounts do not possess unnecessary capabilities related to file system operations unless absolutely required for their role. Furthermore, web server configurations should be hardened to restrict read access to sensitive configuration files like wp-config.php from the web process user where possible, adding a layer of defense-in-depth against path traversal attacks even if application-level validation fails. Regular security audits and static code analysis tools can help identify similar input handling flaws in custom plugins before they are deployed into production environments.