CVE-2023-26209 in FortiDeceptor
Summary
by MITRE • 03/09/2023
A improper restriction of excessive authentication attempts vulnerability [CWE-307] in Fortinet FortiDeceptor 3.1.x and before allows a remote unauthenticated attacker to partially exhaust CPU and memory via sending numerous HTTP requests to the login form.
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Analysis
by VulDB Data Team • 04/02/2023
The vulnerability identified as CVE-2023-26209 represents a critical weakness in Fortinet FortiDeceptor appliances running version 3.1.x and earlier, classified under CWE-307 which specifically addresses improper restriction of excessive authentication attempts. This flaw enables remote attackers to exploit the system's authentication mechanisms without requiring prior authentication credentials, creating a significant security risk for organizations relying on these deception appliances. The vulnerability manifests through the system's insufficient rate limiting and account lockout mechanisms within the web-based login interface, allowing malicious actors to conduct systematic attacks against the authentication service.
The technical implementation of this vulnerability stems from the lack of proper rate limiting controls on the web server's authentication endpoint. When attackers send numerous HTTP requests to the login form, the system fails to adequately monitor and restrict the frequency of these attempts, leading to resource exhaustion. This particular weakness affects the CPU and memory utilization of the FortiDeceptor appliance, as each authentication attempt consumes system resources regardless of whether the credentials are valid or not. The vulnerability specifically targets the web management interface of the device, where the login form serves as the primary attack vector for this type of resource exhaustion attack.
From an operational perspective, this vulnerability presents a substantial risk to network security operations as it allows attackers to degrade system performance and potentially cause service disruption. The partial exhaustion of CPU and memory resources can lead to reduced system responsiveness, slower threat detection capabilities, and potential denial of service conditions that could impact the effectiveness of the deception infrastructure. Organizations using FortiDeceptor appliances may experience degraded performance during active attacks, which could compromise their ability to detect and respond to actual security incidents. The remote nature of this vulnerability means that attackers can exploit it from anywhere on the internet without requiring physical access or valid credentials, making it particularly dangerous in enterprise environments.
The impact of this vulnerability extends beyond simple resource exhaustion to potentially compromise the overall security posture of organizations that depend on FortiDeceptor for threat detection and deception. Attackers could leverage this weakness to perform reconnaissance activities, identify system vulnerabilities, or create conditions that mask actual attacks by consuming system resources. This weakness aligns with several tactics described in the MITRE ATT&CK framework, particularly those related to credential access and resource exhaustion, where adversaries seek to consume system resources to disable security controls or create cover for malicious activities. Organizations should consider implementing network-level protections such as rate limiting at the firewall or load balancer level to mitigate this vulnerability while awaiting vendor patches. The recommended mitigation strategy includes applying the latest firmware updates from Fortinet, implementing network-based rate limiting controls, and monitoring for unusual authentication patterns that may indicate exploitation attempts. Additionally, organizations should review their network segmentation to ensure that management interfaces are not directly exposed to untrusted networks, reducing the attack surface for this type of vulnerability.