CVE-2018-9110 in elFinder
Summary
by MITRE
Studio 42 elFinder before 2.1.37 on Windows has Directory Traversal via the zipdl() function in elFinder.class.php, resulting in file deletion. NOTE: this issue exists because of an incomplete fix for CVE-2018-9109.
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Analysis
by VulDB Data Team • 02/24/2023
The vulnerability CVE-2018-9110 represents a directory traversal flaw in Studio 42 elFinder file manager version 2.1.36 and earlier on Windows systems. This security weakness specifically targets the zipdl() function within the elFinder.class.php file, creating a path traversal condition that allows remote attackers to manipulate file operations. The vulnerability is particularly concerning because it enables unauthorized file deletion operations, which can result in significant data loss and system compromise. The issue stems from an incomplete remediation of a previous vulnerability CVE-2018-9109, indicating a pattern of insufficient security fixes that leave systems vulnerable to exploitation.
The technical implementation of this vulnerability exploits the zipdl() function's inadequate input validation and path handling mechanisms. When processing zip file downloads, the function fails to properly sanitize user-supplied input parameters that control file paths, allowing attackers to manipulate directory traversal sequences such as ..\ or ..%5C. This weakness enables attackers to navigate outside the intended directory boundaries and access or delete files outside the restricted file management scope. The vulnerability specifically affects Windows environments due to differences in path handling and directory separator interpretation between operating systems, making it particularly dangerous in Windows-based web server deployments.
The operational impact of CVE-2018-9110 extends beyond simple file deletion to encompass potential system compromise and data integrity violations. Attackers can leverage this vulnerability to delete critical system files, application binaries, or user data stored within the elFinder-managed directories. The vulnerability also creates opportunities for attackers to escalate privileges or gain unauthorized access to sensitive information stored in adjacent directories. Given that elFinder is commonly used in web applications for file management, this vulnerability can be exploited remotely without authentication, making it particularly dangerous in publicly accessible environments where proper access controls may not be in place.
Organizations affected by CVE-2018-9110 should immediately implement the available patch from Studio 42 elFinder version 2.1.37 or later, which addresses the incomplete fix for CVE-2018-9109. System administrators should conduct comprehensive vulnerability assessments to identify all instances of the vulnerable elFinder version within their infrastructure and ensure proper input validation and path sanitization measures are implemented. Security monitoring should be enhanced to detect suspicious file operations and directory traversal attempts, while access controls should be reviewed to minimize the impact of potential exploitation. This vulnerability aligns with CWE-22 Directory Traversal and relates to ATT&CK techniques involving privilege escalation and data destruction, emphasizing the need for robust input validation and least privilege access controls in web applications.