CVE-2017-14182 in FortiOS
Summary
by MITRE
A Denial of Service (DoS) vulnerability in Fortinet FortiOS 5.4.0 to 5.4.5 allows an authenticated user to cause the web GUI to be temporarily unresponsive, via passing a specially crafted payload to the 'params' parameter of the JSON web API.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 01/21/2021
The vulnerability described in CVE-2017-14182 represents a significant denial of service weakness within Fortinet FortiOS web interface components. This issue affects versions 5.4.0 through 5.4.5 of the FortiOS operating system, which is widely deployed in enterprise network security infrastructures. The vulnerability specifically targets the web GUI functionality, making it particularly concerning given that administrators frequently rely on this interface for critical system management tasks. The flaw manifests when an authenticated user submits a maliciously crafted payload to the 'params' parameter within the JSON web API, resulting in temporary unresponsiveness of the web GUI service.
The technical nature of this vulnerability stems from insufficient input validation within the JSON API processing layer of the FortiOS web interface. When the system receives the specially crafted payload through the 'params' parameter, it fails to properly sanitize or validate the input before processing it within the web GUI context. This inadequate validation creates a condition where the malformed data can cause the web server component to enter a state of temporary unresponsiveness or crash. The vulnerability operates at the application layer and requires authentication, meaning that only users with valid credentials can exploit this weakness, though this does not mitigate its potential impact on network operations.
The operational impact of CVE-2017-14182 extends beyond simple service disruption, as it directly affects the availability of critical network management interfaces. Network administrators who rely on the FortiOS web GUI for configuration changes, monitoring, and troubleshooting could face significant operational challenges when this vulnerability is exploited. The temporary unresponsiveness of the web GUI means that legitimate administrative tasks may be delayed or impossible to perform, potentially leading to extended downtime for network security operations. Organizations with strict compliance requirements or those operating in environments where continuous network availability is critical may experience substantial business disruption from this vulnerability.
This vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic example of how insufficient sanitization of user-supplied data can lead to service availability issues. From an attacker's perspective, this weakness maps to techniques found in the MITRE ATT&CK framework under the T1499 category for network denial of service, where adversaries exploit system weaknesses to disrupt services. The authenticated nature of the attack means that this vulnerability could be exploited by malicious insiders or compromised accounts, making it particularly dangerous in environments where privileged access is not adequately monitored. Organizations should implement immediate mitigations including applying the latest Fortinet security patches, implementing network segmentation to limit access to the web GUI, and establishing monitoring procedures to detect unusual API activity patterns that might indicate exploitation attempts.
The broader implications of this vulnerability highlight the importance of proper input validation in web applications and demonstrate how even authenticated access can create significant security risks when proper sanitization controls are not implemented. Network security teams should consider this vulnerability as part of their comprehensive risk assessment processes, particularly when evaluating the security posture of critical infrastructure components. The remediation approach should include not only patching the specific vulnerability but also implementing broader security controls such as API rate limiting, enhanced authentication mechanisms, and continuous monitoring of administrative access patterns to prevent exploitation.