CVE-2018-20094 in XXL-CONF
Summary
by MITRE
An issue was discovered in XXL-CONF 1.6.0. There is a path traversal vulnerability via ../ in the keys parameter that can download any configuration file, related to ConfController.java and PropUtil.java.
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Analysis
by VulDB Data Team • 06/18/2023
The vulnerability identified as CVE-2018-20094 represents a critical path traversal flaw within the XXL-CONF 1.6.0 configuration management system. This issue stems from inadequate input validation in the keys parameter handling within the ConfController.java and PropUtil.java components, creating a significant security weakness that allows unauthorized access to sensitive configuration files. The vulnerability specifically manifests when the application processes user-supplied input containing ../ sequences, which should normally be restricted to prevent directory traversal attacks.
The technical implementation of this flaw occurs at the application layer where the keys parameter is processed without proper sanitization or validation of directory traversal sequences. When an attacker submits a malicious payload containing ../ characters in the keys parameter, the system fails to properly validate the input before using it to construct file paths. This allows the attacker to navigate beyond the intended directory boundaries and access configuration files that should remain restricted. The vulnerability is particularly dangerous because it directly impacts the core functionality of the configuration management system, potentially exposing sensitive information such as database credentials, API keys, and other confidential parameters that are typically stored in configuration files.
From an operational perspective, this vulnerability presents a severe risk to organizations relying on XXL-CONF for their configuration management needs. Attackers can exploit this weakness to download arbitrary configuration files from the server, potentially gaining access to critical system information that could be used for further attacks or to compromise the entire system. The impact extends beyond simple information disclosure, as configuration files often contain sensitive data that could enable privilege escalation or lateral movement within the network. This vulnerability aligns with CWE-22 Path Traversal and follows patterns commonly associated with ATT&CK technique T1213.002 Access to Configuration Files, making it a significant concern for security teams managing enterprise configuration systems.
Organizations affected by this vulnerability should immediately implement mitigations including input validation and sanitization of all user-supplied parameters, particularly those used in file path construction. The recommended approach involves implementing strict whitelisting of acceptable key values and removing any special characters that could enable directory traversal. Additionally, the application should enforce proper access controls and implement proper authorization checks to ensure that only authorized users can access specific configuration files. Security teams should also consider implementing web application firewalls with rules designed to detect and block path traversal attempts, and conduct thorough code reviews to identify similar vulnerabilities in other components. Regular security updates and patches should be applied to ensure the system remains protected against this and related vulnerabilities, while monitoring systems should be configured to detect unusual access patterns that might indicate exploitation attempts.