CVE-2016-7561 in FortiWLC
Summary
by MITRE
Fortinet FortiWLC 6.1-2-29 and earlier, 7.0-9-1, 7.0-10-0, 8.0-5-0, 8.1-2-0, and 8.2-4-0 allow administrators to obtain sensitive user credentials by reading the pam.log file.
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Analysis
by VulDB Data Team • 05/03/2019
The vulnerability identified as CVE-2016-7561 affects Fortinet FortiWLC wireless LAN controller versions 6.1-2-29 and earlier, as well as several 7.0 and 8.0 series releases. This represents a critical security flaw that allows authenticated administrators to access sensitive user credentials through improper access controls within the system's logging mechanism. The issue stems from the insecure handling of authentication logs that contain user credentials, creating an unauthorized access vector for privileged personnel who should not have such privileges.
The technical implementation of this vulnerability resides in the pam.log file handling within the FortiWLC software architecture. The system fails to properly restrict access to authentication logs that contain sensitive credential information, allowing administrators with sufficient privileges to read these files directly. This flaw operates under the CWE-284 access control weakness category, specifically manifesting as improper access control where administrative users can bypass normal security boundaries to access restricted information. The vulnerability is particularly concerning because it leverages legitimate administrative access to gain access to information that should remain protected even from authorized personnel.
The operational impact of this vulnerability extends beyond simple credential theft, as it enables potential attackers with administrative access to compromise user accounts and escalate their privileges within the wireless network infrastructure. The exposure of user credentials through the pam.log file creates a persistent threat vector that can be exploited to maintain long-term access to the wireless network environment. This vulnerability aligns with ATT&CK technique T1078 legitimate credentials, where adversaries use valid accounts to access systems and maintain persistence. The attack surface is particularly broad given that the FortiWLC serves as a central wireless access point controller, making it a strategic target for network compromise.
Organizations implementing Fortinet FortiWLC solutions must immediately address this vulnerability through proper access control configuration and log management practices. The recommended mitigations include implementing strict file access controls on pam.log files, ensuring that only authorized personnel with legitimate business needs can access authentication logs, and establishing proper audit trails for log file access. Additionally, administrators should implement principle of least privilege access controls and regularly audit administrative access to sensitive system files. The vulnerability also highlights the importance of proper input validation and secure coding practices in system design, particularly when handling sensitive authentication data within log files. Organizations should also consider implementing network segmentation and monitoring solutions to detect unauthorized access attempts to sensitive system files and logs.