CVE-2008-3946 in OpenVMS
Summary
by MITRE
The finger client in HP TCP/IP Services for OpenVMS 5.x allows local users to read arbitrary files via a link corresponding to a (1) .plan or (2) .project file.
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Analysis
by VulDB Data Team • 10/08/2018
The vulnerability described in CVE-2008-3946 represents a critical path traversal flaw within the finger client implementation of HP TCP/IP Services for OpenVMS 5.x systems. This issue stems from inadequate input validation and file access controls within the finger protocol handler, which is designed to provide user information services. The vulnerability specifically affects the client-side implementation where the finger service processes requests for user information, particularly when handling .plan and .project files that are commonly used in Unix-like systems to store user-specific information and project details. The flaw allows local attackers to exploit the client's handling of symbolic links or direct file references to access files outside of the intended directory structure.
The technical mechanism behind this vulnerability operates through the finger client's improper handling of file paths when processing user information requests. When the finger client encounters a request for .plan or .project files, it fails to properly sanitize or validate the file paths, enabling attackers to craft malicious requests that can traverse the file system hierarchy. This vulnerability specifically relates to CWE-22 which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The implementation allows for arbitrary file reading through the finger client interface, effectively bypassing normal file access controls and potentially exposing sensitive system files, configuration data, or user information that should remain protected.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with the capability to access critical system files and user data that may contain passwords, configuration details, or sensitive project information. Local users who can execute the finger client can leverage this flaw to read files that they would normally not have access to, potentially including system configuration files, user credentials, or other sensitive data stored in the system's file structure. This vulnerability particularly affects systems running HP TCP/IP Services for OpenVMS 5.x where the finger service is enabled and accessible to local users, creating a persistent threat vector that could be exploited by both malicious insiders and external attackers who have gained local access to the system. The impact is amplified by the fact that the finger protocol is often enabled by default on many systems and may be accessible to unprivileged users.
Mitigation strategies for this vulnerability should focus on implementing proper input validation and file access controls within the finger client implementation. System administrators should disable the finger service if it is not required for operations, particularly on systems where it is not essential for user information services. The recommended approach involves implementing strict path validation that prevents traversal beyond designated directories and ensuring that symbolic links are properly handled or disabled within the finger client. Additionally, access controls should be enforced to limit which users can execute the finger client and access specific file types. From an ATT&CK perspective, this vulnerability aligns with techniques related to privilege escalation and credential access, as it allows local users to bypass normal file access controls and potentially gain access to sensitive information that could be used for further exploitation. Organizations should also consider implementing monitoring and logging of finger client usage to detect potential exploitation attempts and ensure compliance with security policies that restrict access to sensitive system files.