CVE-2018-11196 in Mahara
Summary
by MITRE
Mahara 17.04 before 17.04.8 and 17.10 before 17.10.5 and 18.04 before 18.04.1 can be used as medium to transmit viruses by placing infected files into a Leap2A archive and uploading that to Mahara. In contrast to other ZIP files that are uploaded, ClamAV (when activated) does not check Leap2A archives for viruses, allowing malicious files to be available for download. While files cannot be executed on Mahara itself, Mahara can be used to transfer such files to user computers.
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Analysis
by VulDB Data Team • 02/11/2020
The vulnerability identified as CVE-2018-11196 affects Mahara learning management systems version 17.04 before 17.04.8 and 17.10 before 17.10.5 and 18.04 before 18.04.1, representing a significant security gap in file validation mechanisms. This flaw stems from the improper handling of Leap2A archive files within the system's upload and scanning processes, creating a vector for malware distribution that bypasses traditional antivirus protections. The vulnerability operates at the intersection of file format handling and security scanning, where the system's security controls fail to adequately inspect specific archive types despite having ClamAV antivirus integration activated.
The technical implementation of this vulnerability lies in the differential treatment of file upload validation processes within Mahara's architecture. While the system correctly implements virus scanning for standard ZIP archives, it fails to apply the same security checks to Leap2A formatted files, which are used for data export and import operations. This creates a false sense of security where users believe their uploads are being scanned for malicious content, but in reality, certain archive formats remain unscanned. The flaw can be categorized under CWE-494 as the system accepts potentially malicious code that could be executed on target systems, and it aligns with ATT&CK technique T1195.001 for the use of malicious files in data transfer operations.
The operational impact of this vulnerability extends beyond simple file transfer capabilities, as it enables attackers to leverage Mahara's legitimate data exchange features to distribute malware. Although the system itself cannot execute files directly, the vulnerability creates a pathway for malicious actors to package harmful content within Leap2A archives that can then be downloaded by unsuspecting users. This scenario represents a sophisticated attack vector where the attacker uses the platform's intended functionality against its own security controls, potentially leading to successful malware delivery on user endpoints. The threat landscape is particularly concerning given that Leap2A is a legitimate export format used for sharing educational content, making the attack more likely to succeed through social engineering or trust-based user behavior.
Organizations using affected Mahara versions face significant risks including potential data breaches, system compromise through malware infections, and reputational damage from successful phishing or malware delivery attacks. The vulnerability essentially creates a backdoor for malicious file transmission that bypasses standard security controls, making it particularly dangerous in educational environments where users may not be security-aware. The attack chain typically involves uploading a Leap2A archive containing malicious files, which then awaits download by other users, potentially leading to widespread infection across the organization's network. Mitigation strategies should focus on immediate patching to the affected versions, implementation of additional file validation layers, and enhanced user education about the risks of downloading content from untrusted sources within the platform. Security teams should also consider implementing network-level monitoring to detect unusual file transfer patterns and ensure that all archive formats are subject to the same antivirus scanning processes regardless of their type or intended use within the system.