CVE-2012-6102 in Moodle
Summary
by MITRE
lib.php in the Submission comments plugin in the Assignment module in Moodle 2.3.x before 2.3.4 and 2.4.x before 2.4.1 allows remote attackers to read or modify the submission comments (aka feedback comments) of arbitrary users via a crafted URI.
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Analysis
by VulDB Data Team • 08/22/2017
The vulnerability identified as CVE-2012-6102 represents a critical access control flaw within the Moodle learning management system's Assignment module. This issue specifically affects the Submission comments plugin in Moodle versions 2.3.x prior to 2.3.4 and 2.4.x prior to 2.4.1, creating a significant security risk for educational institutions relying on the platform for academic submissions and feedback management. The vulnerability stems from improper validation of user permissions within the lib.php file, which governs the submission comments functionality.
The technical exploitation of this vulnerability occurs through a crafted URI manipulation that bypasses normal access controls. Attackers can construct specific URLs that allow them to read or modify feedback comments associated with any user's assignment submissions, regardless of their actual role or permissions within the course. This flaw essentially eliminates the distinction between different user roles such as students, teachers, and administrators, creating a complete breakdown in the permission model that should normally protect sensitive academic data. The vulnerability is classified as a privilege escalation issue under CWE-284, which specifically addresses inadequate access control mechanisms.
The operational impact of this vulnerability extends beyond simple data exposure, as it enables attackers to manipulate academic records and potentially interfere with the educational process. An attacker could modify feedback comments to alter grades, provide false information to students, or even delete critical academic data. This capability undermines the integrity of the entire assignment submission and feedback system, potentially affecting thousands of students across multiple courses if the vulnerability is exploited at scale. The attack vector is particularly dangerous because it requires no authentication for the initial exploitation, making it accessible to anyone who can guess or discover valid URIs.
Organizations using affected Moodle versions should immediately implement mitigation strategies including applying the available security patches that address this specific access control flaw. The vulnerability demonstrates the critical importance of proper input validation and access control implementation in web applications, particularly those handling sensitive educational data. Security monitoring should be enhanced to detect unusual patterns of URI access that might indicate exploitation attempts. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts usage, as attackers can exploit legitimate access paths to gain unauthorized access to academic records. The incident underscores the necessity of regular security assessments and prompt patch management for educational technology platforms that handle sensitive student information and academic records.