CVE-2022-42476 in FortiOS
Summary
by MITRE • 03/07/2023
A relative path traversal vulnerability [CWE-23] in Fortinet FortiOS version 7.2.0 through 7.2.2, 7.0.0 through 7.0.8 and before 6.4.11, FortiProxy version 7.2.0 through 7.2.2 and 7.0.0 through 7.0.8 allows privileged VDOM administrators to escalate their privileges to super admin of the box via crafted CLI requests.
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Analysis
by VulDB Data Team • 03/08/2023
The vulnerability identified as CVE-2022-42476 represents a critical relative path traversal flaw classified under CWE-23 that affects multiple versions of Fortinet FortiOS and FortiProxy products. This vulnerability specifically targets privileged VDOM administrators who possess elevated privileges within their virtual domains, creating a significant security risk that can be exploited to achieve full system compromise. The flaw exists in the command line interface processing mechanisms of these network security appliances, where improper input validation allows attackers to manipulate file paths and gain unauthorized access to system resources that should remain restricted.
The technical exploitation of this vulnerability occurs through carefully crafted CLI requests that leverage the relative path traversal mechanism to bypass normal access controls. When a privileged VDOM administrator submits malicious commands through the CLI interface, the system fails to properly validate the relative paths, allowing the attacker to navigate to directories and files that should be inaccessible. This misconfiguration enables the elevation of privileges from VDOM administrator level to super administrator status, effectively granting full control over the entire Fortinet device. The vulnerability is particularly dangerous because it operates within the legitimate administrative interface, making detection more challenging and allowing attackers to operate under seemingly legitimate administrative sessions.
The operational impact of CVE-2022-42476 extends beyond simple privilege escalation, as it fundamentally compromises the security model of Fortinet's network appliances. Once an attacker achieves super administrator privileges, they can modify system configurations, access sensitive data, install malicious software, and potentially use the compromised device as a pivot point for further attacks within the network. This vulnerability directly violates the principle of least privilege and undermines the multi-domain security architecture that Fortinet implements to isolate different administrative domains. The attack surface is particularly concerning given that VDOM administrators typically have access to multiple virtual domains, making this a potential vector for widespread compromise across different network segments.
Security professionals should implement immediate mitigations including applying the latest Fortinet patches and firmware updates that address this vulnerability, as well as implementing network segmentation and monitoring to detect anomalous CLI activity. Organizations should also review their administrative access controls and ensure that only essential personnel maintain VDOM administrator privileges. The vulnerability aligns with ATT&CK technique T1068 which covers 'Exploitation for Privilege Escalation', and represents a clear example of how improper input validation can lead to critical privilege escalation vulnerabilities. Network administrators should consider implementing additional logging and alerting mechanisms specifically designed to detect path traversal attempts and unusual administrative activities that could indicate exploitation of this vulnerability.