CVE-2017-14185 in FortiOS
Summary
by MITRE
An Information Disclosure vulnerability in Fortinet FortiOS 5.6.0 to 5.6.2, 5.4.0 to 5.4.8 and 5.2 all versions allows SSL VPN web portal users to access internal FortiOS configuration information (eg:addresses) via specifically crafted URLs inside the SSL-VPN web portal.
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Analysis
by VulDB Data Team • 02/25/2026
The CVE-2017-14185 vulnerability represents a critical information disclosure flaw within Fortinet FortiOS SSL VPN implementations that affects multiple version ranges including 5.6.0 through 5.6.2, 5.4.0 through 5.4.8, and all versions of 5.2. This vulnerability specifically targets the SSL VPN web portal functionality where authenticated users can exploit improperly validated input to access sensitive internal configuration data that should remain restricted to administrative personnel. The flaw stems from insufficient validation of user-supplied URLs within the web portal interface, allowing malicious or authorized users to craft specific URL parameters that bypass normal access controls and reveal internal network addresses and configuration details.
The technical implementation of this vulnerability resides in the SSL VPN web portal's URL parsing and access control mechanisms within FortiOS. When users access the SSL VPN portal, the system processes incoming URLs to determine access permissions and content delivery. However, the vulnerability occurs because the system fails to properly sanitize or validate URL parameters before processing them, creating a path traversal or information disclosure condition. This allows an attacker to construct specially crafted URLs that can access internal configuration information including network addresses, routing information, and potentially other sensitive administrative data that should be protected from unauthorized access through the web portal interface.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with valuable network intelligence that can be used for further exploitation. An attacker who gains access to internal network addresses and configuration details can map the internal network topology, identify critical systems, and plan more sophisticated attacks against the infrastructure. This information disclosure can facilitate lateral movement within the network, help identify vulnerable services, and provide insights into network architecture that would otherwise remain hidden from external observers. The vulnerability particularly affects organizations that rely on SSL VPN for remote access, as it undermines the security boundary that the VPN is designed to maintain between internal and external networks.
Organizations affected by CVE-2017-14185 should immediately implement the security patches provided by Fortinet to address the information disclosure vulnerability in their FortiOS implementations. The patch addresses the underlying URL validation issue by implementing proper input sanitization and access control checks within the SSL VPN web portal functionality. Security administrators should also review their current SSL VPN configurations to ensure that access controls are properly implemented and that unnecessary information is not exposed through the web portal interface. Additional mitigations include implementing network segmentation, monitoring for suspicious URL access patterns, and conducting regular security assessments of SSL VPN configurations to identify similar vulnerabilities in other components of the network infrastructure.
This vulnerability aligns with CWE-200, which describes information disclosure vulnerabilities where insufficient protection of sensitive information leads to unauthorized access to system data. From an ATT&CK framework perspective, this vulnerability maps to techniques involving reconnaissance and credential access where adversaries can gather intelligence about internal network structures through information disclosure. The vulnerability demonstrates how seemingly minor access control flaws can have significant operational impacts, particularly in environments where SSL VPN is used as a primary remote access mechanism, and underscores the importance of proper input validation and access control implementation in web-based administrative interfaces. Organizations should treat this as a high-priority vulnerability requiring immediate remediation and ongoing monitoring to prevent exploitation of similar access control weaknesses in their network infrastructure.