CVE-2017-7491 in Moodle
Summary
by MITRE
In Moodle 2.x and 3.x, a CSRF attack is possible that allows attackers to change the "number of courses displayed in the course overview block" configuration setting.
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Analysis
by VulDB Data Team • 09/26/2020
The vulnerability identified as CVE-2017-7491 represents a significant security flaw in Moodle learning management systems affecting versions 2.x and 3.x. This issue stems from inadequate cross-site request forgery protection mechanisms within the platform's administrative configuration handling. The flaw specifically targets the course overview block configuration setting that controls how many courses are displayed to users, making it susceptible to unauthorized modifications through malicious web requests.
This vulnerability operates through a classic cross-site request forgery attack vector where an attacker crafts a malicious request that appears to originate from a legitimate user with administrative privileges. The technical flaw lies in the absence of proper CSRF tokens or validation mechanisms when processing configuration changes for the course overview block. When a user visits a malicious website or clicks on a compromised link, the attacker can trigger configuration changes without the user's knowledge or consent, potentially altering the course display settings to disrupt user experience or create confusion within the learning environment.
The operational impact of this vulnerability extends beyond simple configuration changes, as it represents a potential gateway for more sophisticated attacks within the Moodle ecosystem. An attacker who successfully exploits this vulnerability could manipulate course visibility settings, potentially hiding important courses from students or displaying inappropriate content. This flaw aligns with CWE-352, which specifically addresses cross-site request forgery vulnerabilities, and demonstrates how insufficient input validation and lack of proper session management can compromise system integrity. The attack vector can be particularly dangerous in educational environments where Moodle platforms handle sensitive student data and academic information.
Organizations using affected Moodle versions should implement immediate mitigations including updating to patched versions that incorporate proper CSRF token validation, enabling additional authentication measures for configuration changes, and reviewing user permissions to limit administrative access. The vulnerability also relates to ATT&CK technique T1078 which covers legitimate credentials usage, as unauthorized configuration changes could potentially be used as a foothold for further system compromise. Security administrators should also consider implementing web application firewalls to detect and block suspicious requests targeting administrative endpoints, while conducting regular security audits to ensure proper implementation of CSRF protection mechanisms throughout the platform.