CVE-2019-9960 in LimeSurvey
Summary
by MITRE
The downloadZip function in application/controllers/admin/export.php in LimeSurvey through 3.16.1+190225 allows a relative path.
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Analysis
by VulDB Data Team • 08/04/2023
The vulnerability identified as CVE-2019-9960 resides within LimeSurvey version 3.16.1+190225 in the downloadZip function located in application/controllers/admin/export.php. This flaw represents a directory traversal vulnerability that enables unauthorized access to sensitive files through improper input validation. The issue stems from the application's failure to adequately sanitize user-supplied input when processing zip file downloads, creating an opportunity for malicious actors to manipulate file paths and access restricted system resources. Such vulnerabilities are particularly dangerous in web applications where administrative functions handle sensitive data and system operations.
The technical implementation of this vulnerability allows attackers to exploit a relative path traversal mechanism by manipulating the parameters passed to the downloadZip function. When users interact with the administrative export functionality, the application processes these inputs without sufficient validation or sanitization, permitting attackers to craft malicious requests that traverse directory structures beyond intended boundaries. This weakness directly maps to CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability essentially allows an attacker to specify arbitrary file paths that the application will attempt to process, potentially leading to unauthorized data access, information disclosure, or even remote code execution depending on the system configuration and file permissions.
From an operational perspective, this vulnerability poses significant risks to LimeSurvey installations that handle sensitive survey data, user information, and administrative configurations. The impact extends beyond simple data exposure as it could enable attackers to access database connection files, configuration settings, or other critical system components. The attack surface is particularly concerning in environments where LimeSurvey is deployed with elevated privileges or where administrative access is required for the export functionality. Security analysts should note that this vulnerability aligns with ATT&CK technique T1083, which covers directory and file permissions enumeration, and T1005, covering data from local system, as attackers could leverage this flaw to extract sensitive information from the target system.
Mitigation strategies for CVE-2019-9960 should focus on implementing robust input validation and sanitization mechanisms within the downloadZip function. The recommended approach involves implementing strict path validation that ensures all file paths are properly normalized and restricted to predefined directories. Organizations should immediately upgrade to LimeSurvey versions that have patched this vulnerability, as the maintainers have addressed the issue in subsequent releases. Additionally, implementing proper access controls and least privilege principles for administrative functions can significantly reduce the potential impact of such vulnerabilities. Network segmentation and monitoring of administrative export activities can provide early detection of potential exploitation attempts, while regular security audits should include validation of file handling functions to prevent similar issues in other components of the application.