CVE-2022-40677 in FortiNAC
Summary
by MITRE • 02/16/2023
A improper neutralization of argument delimiters in a command ('argument injection') in Fortinet FortiNAC versions 9.4.0, 9.2.0 through 9.2.5, 9.1.0 through 9.1.7, 8.8.0 through 8.8.11, 8.7.0 through 8.7.6, 8.6.0 through 8.6.5, 8.5.0 through 8.5.4, 8.3.7 allows attacker to execute unauthorized code or commands via specially crafted input parameters.
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Analysis
by VulDB Data Team • 03/16/2023
The vulnerability identified as CVE-2022-40677 represents a critical command injection flaw within Fortinet FortiNAC network access control solutions. This weakness stems from inadequate input validation and sanitization mechanisms that fail to properly neutralize argument delimiters in command execution contexts. The vulnerability affects multiple versions of FortiNAC across several release branches, including versions 9.4.0, 9.2.0 through 9.2.5, 9.1.0 through 9.1.7, 8.8.0 through 8.8.11, 8.7.0 through 8.7.6, 8.6.0 through 8.6.5, and 8.5.0 through 8.5.4, making it a widespread concern for organizations utilizing these network security solutions. The flaw specifically manifests when the system processes user-supplied input parameters that contain command delimiters such as semicolons, ampersands, or other shell metacharacters that can be exploited to inject malicious commands into the underlying operating system.
The technical implementation of this vulnerability aligns with CWE-77, which specifically addresses improper neutralization of special elements used in command execution contexts. Attackers can exploit this weakness by crafting specially formatted input parameters that bypass existing validation checks and inject arbitrary commands into the system's command processing pipeline. This occurs because the FortiNAC system fails to adequately sanitize or escape input data before passing it to system commands, creating an environment where malicious payloads can be executed with the privileges of the affected service account. The vulnerability operates at the command level rather than at the application layer, making it particularly dangerous as it can potentially allow attackers to execute system commands directly on the FortiNAC appliance, bypassing traditional application-level security controls.
The operational impact of CVE-2022-40677 extends beyond simple unauthorized command execution, presenting attackers with potential access to critical network infrastructure management functions. Successful exploitation could enable attackers to escalate privileges, access sensitive network data, modify system configurations, or even establish persistent backdoors within the network access control environment. Given that FortiNAC systems typically serve as central points for network authentication and authorization, this vulnerability could allow attackers to gain unauthorized access to network resources, potentially compromising entire network segments. The attack surface is particularly concerning because FortiNAC appliances often run with elevated privileges and have access to sensitive network information, making them attractive targets for adversaries seeking to establish persistent network access or conduct lateral movement attacks. This vulnerability directly maps to several ATT&CK techniques including T1059.001 for command and script injection, T1068 for exploit for privilege escalation, and T1566 for social engineering tactics that could leverage the compromised system for further network infiltration.
Organizations should implement immediate mitigations including applying the latest security patches released by Fortinet to address this vulnerability, implementing network segmentation to limit access to FortiNAC appliances, and conducting thorough network monitoring for suspicious command execution patterns. The remediation strategy should also include reviewing and strengthening input validation mechanisms within the FortiNAC environment, implementing proper access controls to limit who can submit commands or parameters to the system, and establishing robust logging and alerting mechanisms to detect potential exploitation attempts. Security teams should also consider conducting penetration testing to verify the effectiveness of implemented controls and ensure that no other similar vulnerabilities exist within the FortiNAC deployment or related network infrastructure. Additionally, organizations should review their incident response procedures to ensure they can quickly detect and respond to potential exploitation attempts, as the nature of this vulnerability could allow attackers to maintain persistent access to critical network control systems.