CVE-2017-16787 in Lantime
Summary
by MITRE
The Web Configuration Utility in Meinberg LANTIME devices with firmware before 6.24.004 allows remote authenticated users with certain privileges to read arbitrary files via (1) the ntpclientcounterlogfile parameter to cgi-bin/mainv2 or (2) vectors involving curl support of the "file" schema in the firmware update functionality.
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Analysis
by VulDB Data Team • 07/03/2024
The CVE-2017-16787 vulnerability affects Meinberg LANTIME devices running firmware versions prior to 624004, presenting a critical arbitrary file read flaw within the Web Configuration Utility. This vulnerability stems from insufficient input validation and improper access controls in the device's web interface, specifically targeting the ntpclientcounterlogfile parameter within the cgi-bin/mainv2 endpoint. The flaw enables remote authenticated users with specific privileges to access sensitive files on the device filesystem, potentially exposing system configuration data, logs, and other confidential information.
The technical implementation of this vulnerability involves the exploitation of insecure parameter handling in the web application's backend processing. When the ntpclientcounterlogfile parameter is manipulated, the application fails to properly validate user input before processing file operations, allowing attackers to traverse the filesystem and retrieve arbitrary files. Additionally, the vulnerability extends to the firmware update functionality where curl support for the "file" schema creates an additional attack vector. This secondary vector leverages the underlying curl library's ability to access local files through file:// URLs, bypassing normal file access restrictions and enabling unauthorized file reading during firmware updates.
The operational impact of this vulnerability is significant as it compromises the confidentiality of sensitive system information and potentially enables further exploitation. Attackers can access system logs, configuration files, and other sensitive data that may contain credentials, network configurations, or operational parameters. The vulnerability affects the device's integrity and availability by potentially exposing information that could aid in subsequent attacks, including privilege escalation or network reconnaissance. Organizations relying on Meinberg LANTIME devices for time synchronization and network management face elevated risk of unauthorized access to their time distribution infrastructure.
This vulnerability aligns with CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) and CWE-77 (Improper Neutralization of Special Elements used in a Command) categories, representing path traversal and command injection weaknesses. From an ATT&CK framework perspective, this vulnerability maps to T1083 (File and Directory Discovery) and T1190 (Exploit Public-Facing Application) techniques, demonstrating how attackers can leverage web application flaws to discover and access sensitive files. The vulnerability also relates to T1210 (Exploitation of Remote Services) as it targets remote authenticated access points within network infrastructure devices.
Mitigation strategies for CVE-2017-16787 require immediate firmware updates to version 6.24.004 or later, which address the input validation issues and remove the dangerous curl file schema support in firmware update functionality. Network segmentation should be implemented to limit access to these devices, ensuring only authorized personnel can reach the web configuration interface. Access controls must be strengthened through proper authentication mechanisms and privilege separation, limiting the ability of users to escalate their access. Regular security audits of network infrastructure devices should include verification of firmware versions and configuration settings to prevent similar vulnerabilities from persisting in the environment. Additionally, monitoring for suspicious file access patterns and implementing network intrusion detection systems can help identify exploitation attempts targeting this vulnerability.