CVE-2016-4968 in FortiWan
Summary
by MITRE
The linkreport/tmp/admin_global page in Fortinet FortiWan (formerly AscernLink) before 4.2.5 allows remote authenticated users to discover administrator cookies via a GET request.
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Analysis
by VulDB Data Team • 11/01/2024
The vulnerability identified as CVE-2016-4968 affects Fortinet FortiWan appliances, formerly known as AscernLink, specifically targeting versions prior to 4.2.5. This issue resides within the linkreport/tmp/admin_global page functionality, which serves as a critical administrative interface component. The vulnerability represents a significant security flaw that undermines the integrity of the appliance's authentication mechanisms and exposes sensitive session information to unauthorized parties.
The technical flaw manifests through an improper access control vulnerability that allows remote authenticated users to exploit a GET request mechanism to retrieve administrator cookies. This represents a classic case of information disclosure where the system fails to properly validate user privileges before exposing sensitive session tokens. The vulnerability operates at the application layer and specifically targets the session management component of the web interface, making it particularly dangerous as it enables attackers to escalate their privileges and gain unauthorized administrative access to the appliance.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a pathway for privilege escalation attacks that can ultimately compromise the entire network infrastructure managed by the FortiWan appliance. An attacker who successfully exploits this vulnerability can obtain valid administrator cookies and subsequently assume full administrative privileges over the device, potentially gaining access to network configuration settings, user data, and control over network traffic. This vulnerability directly impacts the confidentiality, integrity, and availability of the affected system, as it enables unauthorized access to critical administrative functions.
This vulnerability aligns with CWE-200, which describes information disclosure vulnerabilities, and represents a clear violation of the principle of least privilege in the context of web application security. The issue also maps to ATT&CK technique T1566, specifically focusing on credential access through the exploitation of weak session management. Organizations utilizing FortiWan appliances should immediately implement mitigations including patching to version 4.2.5 or later, implementing additional access controls, and monitoring for suspicious GET request patterns targeting administrative interfaces. Network segmentation and the implementation of web application firewalls can provide additional defense-in-depth measures to prevent exploitation of this vulnerability.
The broader implications of this vulnerability highlight the critical importance of proper session management and authentication controls in network infrastructure devices. Security professionals should conduct thorough assessments of similar vulnerabilities in other network appliances and ensure that administrative interfaces properly enforce access controls. Regular security updates and vulnerability assessments remain essential practices for maintaining the security posture of network infrastructure components, particularly those handling sensitive administrative functions and session tokens. Organizations should also implement comprehensive monitoring solutions to detect anomalous access patterns that may indicate exploitation attempts against such vulnerabilities.