CVE-2019-16384 in Thinfinity VirtualUI
Summary
by MITRE
Cybele Thinfinity VirtualUI 2.5.17.2 allows ../ path traversal that can be used for data exfiltration. This enables files outside of the web directory to be retrieved if the exact location is known and the user has permissions.
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Analysis
by VulDB Data Team • 06/05/2020
The vulnerability identified as CVE-2019-16384 affects Cybele Thinfinity VirtualUI version 2.5.17.2, representing a critical path traversal flaw that undermines the application's security boundaries. This issue stems from inadequate input validation within the application's file handling mechanisms, specifically when processing user-supplied paths that contain directory traversal sequences such as "../". The vulnerability enables attackers to access files outside the designated web root directory, potentially compromising sensitive data stored in adjacent or parent directories. The flaw exists at the application level where user inputs are not properly sanitized before being used in file system operations, creating an opportunity for malicious actors to exploit the system's file access controls.
The technical implementation of this vulnerability involves the exploitation of relative path references that allow an attacker to navigate beyond the intended file access boundaries. When the application processes requests containing traversal sequences, it fails to validate or sanitize these inputs properly, resulting in the system interpreting the malicious path and granting access to files that should remain restricted. This type of vulnerability falls under the Common Weakness Enumeration category 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's impact is amplified when combined with knowledge of the target system's file structure and existing user permissions, as the attacker must have sufficient privileges to access the target files and must know their exact locations within the file system hierarchy.
The operational impact of CVE-2019-16384 extends beyond simple unauthorized file access, as it provides potential for data exfiltration and system reconnaissance. Attackers can leverage this vulnerability to extract sensitive information including configuration files, user credentials, application source code, and other confidential data stored outside the web directory. The vulnerability's exploitation requires minimal complexity, as it relies on predictable path traversal patterns that can be automated through various attack vectors. This makes the flaw particularly dangerous in environments where the application serves as a gateway to internal systems or where sensitive data is stored in predictable locations relative to the web root. The potential for privilege escalation exists when users with limited access can leverage this vulnerability to access files that require higher permissions, creating a significant risk for organizations relying on the application for remote desktop services and virtualization.
Mitigation strategies for this vulnerability should focus on implementing robust input validation and sanitization mechanisms within the application's file handling components. Organizations should immediately apply the vendor-provided patches or updates that address the path traversal flaw in Thinfinity VirtualUI 2.5.17.2. Additionally, implementing proper access controls and restricting file system permissions can limit the damage that can be caused by successful exploitation attempts. Network-level protections such as web application firewalls and intrusion detection systems can help detect and prevent exploitation attempts by monitoring for suspicious path traversal patterns in incoming requests. The implementation of the principle of least privilege should be enforced, ensuring that application processes run with minimal necessary permissions and that file access is strictly limited to authorized directories. Security monitoring should include regular scanning for similar vulnerabilities in other applications and systems that may be susceptible to the same class of path traversal attacks. Organizations should also consider implementing automated patch management processes to ensure timely remediation of known vulnerabilities, as this particular flaw represents a well-documented attack vector that has been widely exploited in various environments.