CVE-2026-64966 in ATutor
Summary
by MITRE • 08/20/2026
ATutor is vulnerable to a Path Traversal vulnerability in ZIP extraction functionality. An attacker with instructor privileges can upload and extract a specially crafted ZIP archive, causing files to be written outside the intended extraction directory. This allows an attacker to place a server-executable .phtml file in the web root and achieve remote code execution with web server privileges on the underlying server.
Product is no longer actively supported and the vulnerabilities have not been fixed. Only version 2.2.4 was tested and confirmed as vulnerable, other versions were not tested but might also be vulnerable.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in ATutor represents a critical security flaw within its ZIP archive extraction mechanism, specifically classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. This path traversal issue arises from insufficient validation and sanitization of file paths contained within uploaded archives. When an instructor-level user uploads a maliciously crafted ZIP file, the application fails to properly restrict the destination directory for extracted files. Consequently, by utilizing relative path sequences such as dot-dot-slash (../) or absolute path manipulation techniques embedded in the archive's internal filenames, an attacker can force the extraction process to write files outside of the designated upload or temporary directories. This lack of strict boundary enforcement allows the malicious payload to be placed directly into sensitive system locations, most notably the web root directory where server-side scripts are executed by the web server software.
The operational impact of this vulnerability is severe, leading directly to Remote Code Execution (RCE). By successfully writing a PHP-compatible file with an extension such as .phtml or .php into the web root, the attacker gains the ability to execute arbitrary code on the underlying server under the context of the web server process. This typically corresponds to privileges like www-data, apache, or nginx, depending on the specific hosting environment. Once this foothold is established, an attacker can escalate their access further by exploiting local privilege escalation vulnerabilities within the operating system, potentially gaining full control over the host machine. The ability to execute code remotely without authentication beyond the instructor role makes this a high-severity threat that compromises the confidentiality, integrity, and availability of the entire application infrastructure.
From a tactical perspective, this attack vector aligns with MITRE ATT&CK techniques related to Initial Access via Valid Accounts and Execution via Web Shell Deployment. The attacker leverages valid credentials (instructor privileges) to bypass initial authentication controls and then utilizes the file upload feature as a delivery mechanism for malicious code. This is often followed by Command and Control activities where the web shell serves as a persistent backdoor, allowing the adversary to interact with the compromised system remotely. The persistence of this threat is exacerbated by the fact that ATutor is no longer actively supported, meaning there are no official patches or security updates available from the vendor to remediate these flaws.
Given that version 2.2.4 has been confirmed as vulnerable and other versions remain untested but likely susceptible, immediate mitigation strategies must focus on containment rather than patching. Organizations relying on this software should consider isolating it within a restricted network segment or behind strict web application firewalls that can detect and block path traversal patterns in HTTP requests. Additionally, implementing rigorous input validation at the proxy level to reject archives containing suspicious file paths is essential. Since the product is end-of-life, the most robust long-term solution involves migrating to a supported learning management system with active security maintenance. Until such migration occurs, disabling the ZIP upload functionality entirely or restricting it to non-instructor roles can significantly reduce the attack surface and prevent exploitation of this critical vulnerability.