CVE-2023-36634 in FortiAP-U
Summary
by MITRE • 09/13/2023
An incomplete filtering of one or more instances of special elements vulnerability [CWE-792] in the command line interpreter of FortiAP-U 7.0.0, 6.2.0 through 6.2.5, 6.0 all versions, 5.4 all versions may allow an authenticated attacker to list and delete arbitrary files and directory via specially crafted command arguments.
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Analysis
by VulDB Data Team • 10/11/2023
The vulnerability identified as CVE-2023-36634 represents a critical security flaw in the command line interpreter of FortiAP-U devices across multiple firmware versions including 7.0.0, 6.2.0 through 6.2.5, 6.0, and 5.4 series. This issue manifests as an incomplete filtering of special elements, which directly maps to CWE-792, a weakness that occurs when a product does not properly filter or escape special characters in input data. The vulnerability specifically affects the command line interface functionality of these wireless access point devices manufactured by Fortinet, creating a pathway for authenticated attackers to exploit the system's command processing mechanisms.
The technical flaw stems from insufficient sanitization of command line arguments that are processed by the device's interpreter. When an authenticated attacker crafts malicious command arguments containing special characters or sequences, the system fails to adequately filter these inputs before executing the corresponding commands. This incomplete filtering allows attackers to manipulate the command execution flow and potentially bypass intended security restrictions. The vulnerability enables attackers to perform unauthorized file system operations including listing directory contents and deleting arbitrary files, effectively compromising the device's integrity and potentially leading to broader system compromise.
The operational impact of this vulnerability is significant as it provides authenticated attackers with persistent access to critical system functions. Since the attack requires only authentication credentials, the threat surface expands to include compromised user accounts or administrative access that could be obtained through various means such as credential theft or social engineering. The ability to list arbitrary files allows attackers to enumerate system structures and identify sensitive data or configuration files, while the deletion capability can cause service disruption, data loss, or enable further exploitation through the removal of security-critical components. This vulnerability directly impacts the availability and integrity of network infrastructure components and can potentially serve as a foothold for more extensive network penetration.
Organizations utilizing FortiAP-U devices should immediately implement mitigation strategies focusing on firmware updates from Fortinet that address the specific filtering deficiencies in the command line interpreter. The vulnerability aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, where adversaries leverage legitimate system tools to execute malicious commands. Network segmentation and access control measures should be enhanced to limit the scope of potential exploitation, while monitoring systems should be configured to detect unusual command execution patterns. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of the vulnerable firmware versions, and administrative accounts should be protected through strong authentication mechanisms including multi-factor authentication to reduce the risk of unauthorized access to the command line interface.