CVE-2018-9850 in Gxlcms QY
Summary
by MITRE
In Gxlcms QY v1.0.0713, Lib\Lib\Action\Admin\DataAction.class.php allows remote attackers to delete any file via directory traversal sequences in the id parameter of an Admin-Data-del request.
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Analysis
by VulDB Data Team • 01/23/2020
The vulnerability identified as CVE-2018-9850 affects Gxlcms QY version 1.0.0713 and represents a critical directory traversal flaw within the administrative data handling component of the content management system. This vulnerability exists in the Lib\Lib\Action\Admin\DataAction.class.php file where the application fails to properly validate or sanitize user input parameters, specifically the id parameter used in Admin-Data-del requests. The flaw allows remote attackers to manipulate file paths through malicious directory traversal sequences, enabling unauthorized deletion of arbitrary files on the server filesystem.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization mechanisms within the application's data deletion functionality. When an attacker submits a malicious id parameter containing directory traversal sequences such as ../ or ..\, the application processes these sequences without proper restriction, allowing the deletion operation to target files outside the intended directory scope. This type of vulnerability falls under CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The vulnerability enables attackers to bypass normal access controls and potentially delete critical system files, configuration files, or user data that resides outside the application's intended file access boundaries.
From an operational impact perspective, this vulnerability poses significant risks to system integrity and availability. Attackers can leverage this flaw to delete essential application files, database files, or even system-critical components, potentially leading to complete application failure or system compromise. The remote nature of the attack means that adversaries do not require physical access or local system credentials to exploit this vulnerability, making it particularly dangerous in web-facing environments. The impact extends beyond simple file deletion as it can facilitate further attacks by allowing attackers to remove security-related files, logs, or backup copies that might otherwise prevent or detect malicious activities.
The exploitation of this vulnerability aligns with several tactics outlined in the MITRE ATT&CK framework, particularly those related to privilege escalation and persistence. Attackers can use this initial foothold to remove security monitoring files or logs that would otherwise detect their activities, thereby establishing a more persistent presence within the compromised system. The vulnerability also enables data destruction and denial of service attacks, which are common tactics used by malicious actors to disrupt business operations or gain unauthorized access to sensitive information. Organizations should consider implementing comprehensive monitoring solutions that can detect unusual file deletion patterns and anomalous administrative requests to identify potential exploitation attempts.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security improvements. The primary solution involves implementing strict input validation and sanitization for all user-supplied parameters, particularly those used in file operations. This includes normalizing file paths, implementing whitelist validation for acceptable file names and paths, and ensuring that all directory traversal sequences are properly rejected or escaped. Organizations should also apply the latest security patches provided by the software vendor and implement proper access controls to limit administrative privileges to only authorized personnel. Additionally, deploying web application firewalls and implementing proper logging and monitoring mechanisms can help detect and prevent exploitation attempts. The vulnerability demonstrates the critical importance of secure coding practices and proper input validation in preventing directory traversal attacks, which remain a persistent threat in web applications.