CVE-2006-4942 in Moodle
Summary
by MITRE
Moodle before 1.6.2, when the configuration lacks (1) algebra or (2) tex filters, allows remote authenticated users to write LaTeX or MimeTeX output files to the top level of the dataroot directory via (a) filter/algebra/pix.php or (b) filter/tex/pix.php.
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Analysis
by VulDB Data Team • 08/04/2018
This vulnerability exists in Moodle versions prior to 1.6.2 and represents a critical directory traversal and file creation flaw that can be exploited by authenticated remote attackers. The vulnerability stems from insufficient input validation and improper file handling within the algebra and tex filter components of the learning management system. When the system lacks proper algebra or tex filters configuration, the filter/algebra/pix.php and filter/tex/pix.php scripts become susceptible to malicious file creation attacks in the dataroot directory's top level. The flaw allows attackers to inject and execute arbitrary LaTeX or MimeTeX output files directly into the system's data storage area, bypassing normal file permissions and security controls. This represents a significant security risk as it enables attackers to potentially place malicious files in critical system locations, potentially leading to arbitrary code execution or data compromise. The vulnerability falls under CWE-22 which specifically addresses path traversal and directory traversal issues, where improper validation of file paths allows attackers to access or create files outside of intended directories. From an operational perspective, this vulnerability can be exploited through legitimate authenticated user sessions, making it particularly dangerous as it can be leveraged by insiders or compromised accounts. The attack vector involves crafting malicious input that gets processed by the vulnerable filter scripts, resulting in unauthorized file creation in the dataroot directory. This vulnerability aligns with ATT&CK technique T1059 which covers execution through command and scripting interpreters, as attackers could potentially use this flaw to place malicious files that could be executed later by the system. The impact extends beyond simple file creation, as the dataroot directory typically contains user data, course materials, and system configuration files. Attackers could potentially use this vulnerability to upload malicious scripts, backdoors, or other payloads that could compromise the entire Moodle installation. The vulnerability also has implications for data integrity and confidentiality, as unauthorized files could be created that might interfere with legitimate system operations or contain malicious content designed to exfiltrate data. Organizations using Moodle versions prior to 1.6.2 should immediately implement the available security patches or upgrade to patched versions. Additionally, administrators should review their filter configurations to ensure proper algebra and tex filters are enabled and properly configured. Network segmentation and access controls should be implemented to limit the potential impact of such vulnerabilities, and monitoring should be enhanced to detect unauthorized file creation activities in the dataroot directory. Regular security audits and vulnerability assessments should be conducted to identify and remediate similar issues in other components of the system. The vulnerability demonstrates the importance of proper input validation and secure file handling practices in web applications, particularly those dealing with user-generated content and system configuration files.