CVE-2008-3940 in OpenVMS
Summary
by MITRE
Format string vulnerability in the finger client in HP TCP/IP Services for OpenVMS 5.x allows local users to gain privileges via format string specifiers in a (1) .plan or (2) .project file.
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Analysis
by VulDB Data Team • 10/08/2018
The vulnerability identified as CVE-2008-3940 represents a critical format string vulnerability within the finger client component of HP TCP/IP Services for OpenVMS 5.x versions. This flaw exists in the client-side implementation that processes user information files, specifically targeting the .plan and .project file formats that are commonly used in Unix-like systems to store user information and project details. The vulnerability arises from insufficient input validation and improper handling of format specifiers within these user-defined files, creating a pathway for privilege escalation attacks.
The technical exploitation of this vulnerability occurs when a local user crafts malicious content within their .plan or .project file that contains format string specifiers such as %x, %s, or %n. When the finger client processes these files to display user information, it fails to properly sanitize the input before passing it to formatting functions. This improper handling allows attackers to manipulate memory contents, potentially leading to arbitrary code execution or privilege escalation. The vulnerability is particularly dangerous because it operates at the local user level, meaning any user with access to modify their own files can potentially exploit this weakness to gain elevated privileges.
From an operational impact perspective, this vulnerability compromises the integrity and security of OpenVMS systems running HP TCP/IP Services 5.x. The local privilege escalation capability means that attackers can potentially elevate their privileges from standard user level to administrative levels, providing access to sensitive system resources, configuration files, and other users' data. The attack vector is relatively simple to execute, requiring only local file modification capabilities and the ability to trigger the finger client functionality. This makes the vulnerability particularly concerning for systems where multiple users have local access, as it could be exploited without external network access or sophisticated attack techniques.
Security professionals should note that this vulnerability aligns with CWE-134, which specifically addresses format string vulnerabilities where format strings are constructed from user-controlled data. The attack pattern follows typical privilege escalation techniques described in the MITRE ATT&CK framework under the Privilege Escalation tactic. Organizations should implement immediate mitigations including applying the vendor-provided patches for HP TCP/IP Services, restricting write permissions on user home directories, and monitoring for unauthorized modifications to .plan and .project files. Additionally, system administrators should consider disabling unnecessary services and implementing proper access controls to limit local user capabilities that could be leveraged for exploitation. The vulnerability underscores the importance of input validation and proper string handling in security-critical applications, particularly in enterprise operating systems where privilege separation is essential for maintaining system integrity.