CVE-2017-1000140 in Mahara
Summary
by MITRE
Mahara 1.8 before 1.8.7 and 1.9 before 1.9.5 and 1.10 before 1.10.3 and 15.04 before 15.04.0 are vulnerable to a maliciously created .xml file that can have its code executed when user tries to download the file.
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Analysis
by VulDB Data Team • 12/04/2019
The vulnerability identified as CVE-2017-1000140 represents a critical server-side request forgery and code execution flaw affecting multiple versions of the Mahara learning management system. This vulnerability stems from inadequate input validation and sanitization mechanisms within the application's file handling processes, specifically when processing xml files. The flaw allows attackers to craft malicious xml files that, when downloaded by authenticated users, execute arbitrary code on the target system. This vulnerability falls under the CWE-94 category of Code Injection, specifically representing a server-side code execution vulnerability that can be exploited through improper handling of user-supplied data.
The technical implementation of this vulnerability occurs when Mahara processes xml files during download operations, failing to properly validate or sanitize the xml content before execution. Attackers can construct malicious xml files containing embedded code or references to external resources that get executed when users attempt to download these files. The vulnerability exists across multiple version lines including 1.8.x before 1.8.7, 1.9.x before 1.9.5, 1.10.x before 1.10.3, and 15.04 before 15.04.0, indicating a widespread issue affecting the application's core file processing functionality. This type of vulnerability is particularly dangerous as it leverages legitimate user actions to execute malicious code, making it difficult to detect through traditional network monitoring approaches.
The operational impact of CVE-2017-1000140 is severe and multifaceted, potentially allowing attackers to gain full system compromise, data exfiltration, and persistence within affected environments. When exploited, the vulnerability can enable attackers to execute arbitrary commands on the server hosting Mahara, potentially leading to complete system takeover. The attack vector requires user interaction through legitimate download operations, making it particularly insidious as it can bypass many traditional security controls that rely on network-based detection. This vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter, specifically targeting server-side execution capabilities. The impact extends beyond immediate code execution to include potential privilege escalation, data corruption, and unauthorized access to sensitive educational information stored within the learning management system.
Organizations affected by this vulnerability should immediately implement mitigations including upgrading to patched versions of Mahara, specifically versions 1.8.7, 1.9.5, 1.10.3, and 15.04.0 respectively. Additional protective measures should include implementing strict file type validation, disabling xml file downloads where possible, and monitoring for suspicious file download activities. Network segmentation and access controls should be reinforced to limit potential lateral movement if exploitation occurs. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege in web application security. Organizations should also consider implementing web application firewalls and content security policies to detect and prevent malicious xml file processing. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other applications within the organization's infrastructure, as this type of flaw commonly appears in applications with inadequate sanitization of user-supplied content.