CVE-2018-16397 in LimeSurvey
Summary
by MITRE
In LimeSurvey before 3.14.7, an admin user can leverage a "file upload" question to read an arbitrary file,
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Analysis
by VulDB Data Team • 03/20/2020
The vulnerability described in CVE-2018-16397 represents a critical security flaw in LimeSurvey versions prior to 3.14.7 that allows administrative users to exploit file upload functionality to access arbitrary files on the server. This vulnerability falls under the category of insecure file handling and arbitrary file access, which can be categorized under CWE-22 - Improper Limitation of a Pathname to a Restricted Directory and CWE-23 - Improper Limitation of a Pathname to a Restricted Directory. The flaw specifically affects the "file upload" question type within LimeSurvey's survey creation interface, where administrators can potentially leverage this functionality to read files that should normally be restricted from access.
The technical implementation of this vulnerability stems from insufficient input validation and path traversal controls within the file upload processing mechanism. When administrators create survey questions using the file upload feature, the system fails to properly sanitize or validate file paths that may contain directory traversal sequences or references to system files. Attackers with administrative privileges can craft malicious file upload parameters that bypass normal file access controls, allowing them to read sensitive files such as configuration files, database credentials, application source code, or other system resources that should remain protected. This represents a privilege escalation vulnerability where administrative access is leveraged to gain unauthorized file system access.
The operational impact of this vulnerability is significant for organizations relying on LimeSurvey for data collection and survey management. An attacker with administrative access can extract sensitive information including database connection strings, encryption keys, application configuration details, and potentially even user data stored in the system. The vulnerability enables data exfiltration and can serve as a stepping stone for further attacks within the network environment. Organizations may experience compliance violations and data breaches when such vulnerabilities are exploited, particularly in regulated environments where data protection is mandatory. The attack vector is particularly dangerous because it requires only administrative privileges, which are often more limited in scope than full system access but still provide sufficient capability to exploit this specific vulnerability.
Mitigation strategies for CVE-2018-16397 primarily involve upgrading to LimeSurvey version 3.14.7 or later, which includes proper input validation and path restriction controls for file upload operations. Organizations should also implement additional security measures such as restricting administrative privileges to only necessary personnel, implementing strict file upload validation rules, and monitoring file access patterns for unusual activity. The vulnerability aligns with ATT&CK technique T1078 - Valid Accounts and T1005 - Data from Local System, as it leverages administrative credentials to access system files and data. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other applications, and organizations should maintain updated security patches to protect against known vulnerabilities in their software inventory.