CVE-2015-5264 in Moodle
Summary
by MITRE
The lesson module in Moodle through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2 allows remote authenticated users to bypass intended access restrictions and enter additional answer attempts by leveraging the student role.
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Analysis
by VulDB Data Team • 07/08/2022
The vulnerability identified as CVE-2015-5264 resides within the lesson module of the Moodle learning management system, affecting versions through 2.6.11, 2.7.x before 2.7.10, 2.8.x before 2.8.8, and 2.9.x before 2.9.2. This security flaw represents a critical access control issue that undermines the intended security model of educational platforms. The vulnerability specifically targets the authorization mechanisms within Moodle's lesson module, where users with the student role can exploit a design flaw to gain unauthorized access to additional answer attempts during lesson activities. This represents a significant bypass of the system's intended access restrictions, allowing unauthorized privilege escalation within the educational environment.
The technical implementation of this vulnerability stems from insufficient input validation and access control checks within the lesson module's handling of user interactions. When authenticated students attempt to engage with lesson activities, the system fails to properly verify whether the user should be permitted to submit additional answer attempts beyond their intended limits. This flaw operates through a combination of inadequate session management and insufficient privilege validation, where the system does not properly distinguish between legitimate user actions and malicious attempts to circumvent lesson restrictions. The vulnerability essentially allows authenticated users to manipulate the lesson module's internal state, effectively granting them additional attempts without proper authorization. This type of flaw aligns with CWE-285, which addresses improper authorization issues in software systems, and specifically relates to the broader category of access control vulnerabilities.
The operational impact of CVE-2015-5264 extends beyond simple privilege escalation, creating potential for academic integrity violations and system compromise within educational institutions. When exploited, this vulnerability enables students to potentially access unlimited answer attempts, which could lead to cheating during assessments, undermine the validity of grade reporting, and compromise the integrity of learning outcomes. Educational institutions relying on Moodle for assessment and lesson delivery face significant risks including unauthorized data manipulation, potential grade inflation, and the possibility of students gaining unfair advantages in academic settings. The vulnerability also creates opportunities for further exploitation as attackers could potentially use this initial access to explore other system components or escalate privileges further. This aligns with ATT&CK technique T1078 which covers valid accounts usage and privilege escalation through legitimate system access points.
Organizations should implement immediate mitigation strategies including applying the latest security patches available from Moodle's official release cycle, as this vulnerability was addressed in subsequent versions of the platform. System administrators must also conduct thorough security audits of their Moodle installations to identify any potential exploitation attempts and ensure that proper access controls are enforced. Additional protective measures include implementing network segmentation to limit access to Moodle systems, monitoring user activities for unusual patterns that might indicate exploitation attempts, and establishing proper role-based access controls to prevent unauthorized access to lesson modules. Regular security assessments and vulnerability scanning should be conducted to identify similar issues within the educational platform ecosystem. The vulnerability demonstrates the importance of maintaining up-to-date software versions and implementing robust security controls in educational technology environments where sensitive academic data and assessment integrity are at stake.