CVE-2013-4938 in Moodle
Summary
by MITRE
The LTI (aka IMS-LTI) mod_form implementation in Moodle through 2.1.10, 2.2.x before 2.2.11, 2.3.x before 2.3.8, 2.4.x before 2.4.5, and 2.5.x before 2.5.1 does not properly support the sendname, sendemailaddr, and acceptgrades settings, which allows remote attackers to obtain sensitive information in opportunistic circumstances by leveraging an environment in which there was an ineffective attempt to enable the more secure values.
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Analysis
by VulDB Data Team • 02/28/2019
The vulnerability described in CVE-2013-4938 affects the Learning Tools Interoperability module implementation within Moodle, a widely deployed open-source learning management system. This issue specifically targets the mod_form component responsible for handling LTI tool configurations, which enables integration with external learning applications and services. The flaw exists across multiple Moodle versions including 2.1.10 and earlier, 2.2.x versions before 2.2.11, 2.3.x versions before 2.3.8, 2.4.x versions before 2.4.5, and 2.5.x versions before 2.5.1, indicating a prolonged period of exposure affecting the core LTI functionality.
The technical flaw stems from inadequate implementation of the sendname, sendemailaddr, and acceptgrades configuration settings within the LTI module's form handling mechanism. These settings are designed to control what user information is shared with external LTI tools and whether grade information can be transmitted back to the learning management system. When these security parameters are not properly enforced, attackers can exploit the misconfiguration to access sensitive user data including names and email addresses, as well as potentially manipulate grade information. This represents a critical failure in the principle of least privilege and proper access control enforcement within the LTI integration framework.
The operational impact of this vulnerability is significant for educational institutions relying on Moodle for their learning management needs. Attackers can leverage opportunistic conditions to extract user information from environments where security configurations were not properly implemented or enforced. This creates a data exposure risk that could lead to privacy violations, identity theft, and potential credential compromise. The vulnerability is particularly dangerous because it operates in an environment where effective security measures were already in place but were rendered ineffective due to the flawed implementation, creating a false sense of security for administrators.
Organizations should immediately apply the relevant security patches for their Moodle installations to address this vulnerability. System administrators should conduct comprehensive audits of their LTI tool configurations to ensure that sendname, sendemailaddr, and acceptgrades settings are properly configured according to security best practices. The implementation should follow the principle of least privilege where external tools only receive the minimum information necessary for their functionality. Additionally, regular security assessments of LTI integrations should be performed to identify and remediate similar configuration weaknesses. This vulnerability aligns with CWE-200 (Information Exposure) and represents a typical example of insecure configuration management that can be addressed through proper security hardening practices and adherence to the security controls outlined in the NIST Cybersecurity Framework and ISO 27001 standards.