CVE-2019-5884 in elFinder
Summary
by MITRE
php/elFinder.class.php in elFinder before 2.1.45 leaks information if PHP's curl extension is enabled and safe_mode or open_basedir is not set.
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Analysis
by VulDB Data Team • 06/26/2023
The vulnerability identified as CVE-2019-5884 affects the elFinder file manager component, specifically within the php/elFinder.class.php file version prior to 2.1.45. This information disclosure flaw arises from the application's improper handling of PHP's curl extension when certain server configurations are present. The vulnerability manifests when the PHP curl extension is enabled on the server but the safe_mode and open_basedir restrictions are not configured, creating a security gap that allows unauthorized information leakage.
The technical implementation of this vulnerability stems from the elFinder application's lack of proper input validation and output sanitization when processing file operations. When PHP's curl extension is active and the server configuration does not enforce safe_mode or open_basedir restrictions, the application fails to properly isolate file system access requests. This creates an environment where malicious actors can potentially enumerate file system structures and access sensitive information through crafted requests that leverage the curl functionality. The flaw essentially allows for directory traversal and file listing operations that should be restricted by default security configurations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with valuable reconnaissance data that can be used for subsequent exploitation attempts. An attacker who successfully exploits this vulnerability can gain knowledge about the underlying file system structure, potentially identifying sensitive files, configuration data, or system paths that could aid in further attacks. The vulnerability is particularly concerning because it leverages default PHP configurations that many servers may not explicitly secure, making it a widespread risk across various deployments. This type of information leakage can facilitate more sophisticated attacks such as local file inclusion, remote code execution, or privilege escalation attempts.
The vulnerability aligns with CWE-200, which addresses "Information Exposure," and represents a classic case of insufficient input validation combined with inadequate output filtering. From an ATT&CK framework perspective, this vulnerability maps to techniques involving reconnaissance and initial access phases, specifically T1083 (File and Directory Discovery) and T1592 (Gather Victim Host Information). Organizations should consider implementing mitigations that include updating to elFinder version 2.1.45 or later, which contains patches addressing this information disclosure issue. Additionally, system administrators should ensure that PHP's safe_mode and open_basedir restrictions are properly configured to limit file system access, and that the curl extension is properly secured through appropriate configuration settings. Network segmentation and access controls should also be implemented to reduce the potential impact of such information leakage, while regular security audits should verify that the application is not vulnerable to similar configuration-based attacks.