CVE-2013-4604 in FortiOS
Summary
by MITRE
Fortinet FortiOS before 5.0.3 on FortiGate devices does not properly restrict Guest capabilities, which allows remote authenticated users to read, modify, or delete the records of arbitrary users by leveraging the Guest role.
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Analysis
by VulDB Data Team • 05/17/2021
The vulnerability identified as CVE-2013-4604 affects Fortinet FortiOS versions prior to 5.0.3 on FortiGate devices, representing a critical authorization flaw that undermines the security model of these network appliances. This issue stems from insufficient access control mechanisms within the Guest role implementation, creating a privilege escalation vector that allows authenticated users with minimal permissions to perform administrative actions against other users' data. The flaw exists in the core user management and access control subsystems of the FortiOS operating system, specifically within the Guest user role configuration where proper authorization boundaries are not enforced.
The technical implementation of this vulnerability involves a lack of proper input validation and access control checks when processing user management requests from Guest accounts. When authenticated users with Guest privileges attempt to manipulate user records, the system fails to verify whether the requesting user has legitimate authorization to perform such operations on target accounts. This weakness aligns with CWE-285, which addresses improper authorization within software systems, and demonstrates how insufficient privilege checking can lead to unauthorized data manipulation. The vulnerability allows attackers to execute read, modify, or delete operations on arbitrary user records without proper authentication, effectively breaking the principle of least privilege that should govern all user interactions within the system.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on FortiGate devices for network security. Remote authenticated users can exploit this flaw to access sensitive user information, alter user configurations, or completely remove user accounts, potentially disrupting network services and compromising user privacy. The impact extends beyond simple data manipulation as it can enable attackers to gain deeper insights into user behavior patterns, access restricted resources, or even facilitate further attacks by deleting user accounts and creating new ones with elevated privileges. This vulnerability directly maps to ATT&CK technique T1078 which covers valid accounts and privilege escalation through legitimate user credentials, making it particularly dangerous in environments where multiple users share the same network infrastructure.
Organizations affected by this vulnerability should immediately implement the Fortinet-published security patches for FortiOS versions 5.0.3 and later, which address the improper access control implementation in the Guest role. Network administrators must also review and tighten user role assignments to ensure that Guest accounts have minimal necessary permissions and that proper role-based access controls are enforced. Additional mitigations include implementing network segmentation to limit Guest access to sensitive systems, conducting regular audits of user account permissions, and establishing monitoring procedures to detect unusual user activity patterns that might indicate exploitation attempts. The vulnerability highlights the importance of proper access control design and the need for comprehensive testing of role-based permission systems to prevent unauthorized data manipulation in enterprise network security appliances.