CVE-2019-9708 in Mahara
Summary
by MITRE
An issue was discovered in Mahara 17.10 before 17.10.8, 18.04 before 18.04.4, and 18.10 before 18.10.1. A site administrator can suspend the system user (root), causing all users to be locked out from the system.
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Analysis
by VulDB Data Team • 06/07/2020
The vulnerability identified as CVE-2019-9708 represents a critical access control flaw within the Mahara learning management system that affects multiple version streams including 17.10.8, 18.04.4, and 18.10.1. This issue stems from a design weakness that allows a malicious or compromised site administrator to manipulate the system's user account hierarchy by suspending the root user account, effectively creating a denial of service scenario for all legitimate users. The vulnerability is classified under CWE-284 Access Control Bypass, which specifically addresses inadequate access control mechanisms that permit unauthorized access to system resources or privileges. The flaw resides in the system's privilege management architecture where the root user account is not properly protected from administrative actions that could compromise system availability.
The technical implementation of this vulnerability exploits the inherent trust model within Mahara's administrative interface where site administrators possess elevated privileges that should not extend to critical system accounts. When a site administrator suspends the root user account, the system loses its ability to maintain proper authentication and authorization functions because the root account serves as a critical system account that typically maintains administrative access to core system functions. This suspension effectively creates a cascading failure where all users lose access to the system, as the authentication mechanisms rely on the root account's continued availability for proper system operation. The vulnerability demonstrates poor separation of privileges and inadequate protection of system-critical accounts from administrative actions that could impact system availability.
The operational impact of CVE-2019-9708 extends beyond simple service disruption to represent a fundamental compromise of system integrity and availability. Organizations utilizing affected Mahara versions face the risk of complete system lockout where all legitimate users, including students, instructors, and administrators, are denied access to educational content and system functionality. This vulnerability particularly affects educational institutions that rely heavily on continuous access to learning management systems, potentially disrupting entire academic programs and creating significant operational challenges. The attack vector requires only that an attacker gain access to a site administrator account, which may occur through credential theft, social engineering, or exploitation of other vulnerabilities, making the attack surface relatively broad. The vulnerability also aligns with ATT&CK technique T1078 Valid Accounts, as it leverages legitimate administrative privileges to achieve system compromise.
Mitigation strategies for CVE-2019-9708 require both immediate patching and operational security enhancements to prevent unauthorized administrative access. Organizations should prioritize upgrading to patched versions of Mahara 17.10.8, 18.04.4, or 18.10.1 to resolve the underlying access control flaw. Additionally, implementing strict privilege separation and role-based access controls should be enforced to prevent any single administrator account from having the ability to suspend critical system accounts. Network segmentation and multi-factor authentication for administrative accounts should be implemented to reduce the risk of credential compromise. The security architecture should include monitoring mechanisms to detect attempts to suspend critical accounts and alert system administrators to potential malicious activity. Regular security audits should verify that system accounts are properly protected from administrative actions that could impact system availability, ensuring that the root account maintains its protected status within the system's privilege hierarchy.