CVE-2013-2243 in Moodle
Summary
by MITRE
mod/lesson/pagetypes/matching.php in Moodle through 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 allows remote authenticated users to obtain sensitive answer information by reading the HTML source code of a document.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 01/04/2022
The vulnerability identified as CVE-2013-2243 resides within the Moodle learning management system and specifically affects versions through 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. This issue manifests in the mod/lesson/pagetypes/matching.php component which handles matching question types within the lesson module. The flaw represents a critical information disclosure vulnerability that allows authenticated attackers to access sensitive answer data through simple source code inspection techniques. The vulnerability stems from inadequate input validation and output sanitization mechanisms within the matching question rendering process, where answer information is inadvertently exposed in the HTML source code of generated lesson pages.
The technical implementation of this vulnerability occurs when Moodle processes matching questions within lesson modules. During the rendering of matching question pages, the system fails to properly sanitize or obfuscate answer data that should remain confidential to prevent unauthorized access. When authenticated users access lesson pages containing matching questions, the HTML source code reveals the correct answer mappings in a format that can be easily read and extracted. This exposure occurs because the matching.php script does not adequately separate the presentation layer from the data layer, allowing sensitive answer information to be directly embedded in the HTML output without proper access controls or data protection mechanisms. The vulnerability is classified under CWE-200 as "Information Exposure" and specifically relates to CWE-502 which deals with improper handling of sensitive information.
The operational impact of this vulnerability extends beyond simple information disclosure to potentially compromise the integrity of assessment processes within Moodle environments. Attackers with authenticated access can exploit this weakness to gain knowledge of correct answers to matching questions, which undermines the educational assessment process and creates opportunities for cheating or academic dishonesty. The vulnerability affects educational institutions that rely on Moodle for online assessments, potentially compromising the validity of exam results and academic integrity. Additionally, the exposure of answer information could enable attackers to develop targeted strategies for bypassing security measures or to create tools that automate the process of extracting correct responses, making the vulnerability particularly dangerous in high-stakes educational environments. This issue aligns with ATT&CK technique T1566 which involves credential access through social engineering and information gathering techniques.
Organizations should implement immediate mitigations to address this vulnerability by upgrading to patched versions of Moodle where available, specifically versions 2.3.8, 2.4.5, and 2.5.1 or later. System administrators should also consider implementing additional access controls and monitoring mechanisms to detect unauthorized access patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and output sanitization in web applications, particularly when handling sensitive educational data. Security teams should conduct thorough assessments of their Moodle installations to identify any other components that might exhibit similar information disclosure characteristics, as this vulnerability highlights broader security concerns within the platform's architecture. Regular security audits and vulnerability assessments should be implemented to prevent similar issues from arising in future releases, emphasizing the need for robust security practices throughout the software development lifecycle.