CVE-2015-1458 in FortiAuthenticator
Summary
by MITRE
Fortinet FortiAuthenticator 3.0.0 allows local users to bypass intended restrictions and gain privileges by creating /tmp/privexec/dbgcore_enable_shell_access and executing the "shell" command.
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Analysis
by VulDB Data Team • 04/12/2022
The vulnerability identified as CVE-2015-1458 affects Fortinet FortiAuthenticator version 3.0.0, representing a critical local privilege escalation flaw that undermines the system's security controls. This issue stems from improper access control mechanisms within the authentication platform, which is designed to manage user authentication and authorization processes for network security environments. The vulnerability specifically targets the system's handling of debug and administrative functions, creating an unauthorized access pathway that bypasses normal security restrictions.
The technical implementation of this vulnerability involves a simple yet effective attack vector that exploits a hardcoded file path in the system's temporary directory structure. Local attackers can create a specific file named /tmp/privexec/dbgcore_enable_shell_access which serves as a trigger mechanism for privilege escalation. This file creation activates a debug functionality that was intended for legitimate troubleshooting purposes but has been improperly exposed to local users. The system's failure to validate file access permissions for this debug mechanism allows unauthorized local accounts to execute the "shell" command with elevated privileges, effectively bypassing the normal authentication and authorization controls that should prevent such access.
From an operational impact perspective, this vulnerability transforms a local user account into a privileged administrator with full system access capabilities. The attack requires only local system access and basic file manipulation skills, making it particularly dangerous in environments where local accounts might be compromised or where users have legitimate access to the system. The vulnerability directly violates fundamental security principles of least privilege and principle of least functionality, as it allows unauthorized elevation of privileges without proper authentication or authorization checks. This creates a significant risk for organizations relying on FortiAuthenticator for security management, as local attackers can potentially access sensitive system configurations, user data, and administrative functions.
The vulnerability aligns with CWE-276, which addresses improper file permissions, and reflects weaknesses in access control mechanisms that should prevent unauthorized privilege escalation. From an attack framework perspective, this vulnerability maps to ATT&CK technique T1068, which covers 'Local Privilege Escalation', and T1059, which encompasses 'Command and Scripting Interpreter' as attackers can execute shell commands with elevated privileges. Organizations should implement immediate mitigations including restricting local file system access, removing or securing the debug file path, and applying Fortinet's official security patches. The recommended approach involves disabling unnecessary debug functionality, implementing proper file permission controls, and conducting regular security audits to identify similar privilege escalation vectors within the system's architecture. Additionally, system administrators should monitor for unauthorized file creation in sensitive directories and implement logging controls to detect potential exploitation attempts of this and similar vulnerabilities.