CVE-2016-7542 in FortiOS
Summary
by MITRE
A read-only administrator on Fortinet devices with FortiOS 5.2.x before 5.2.10 GA and 5.4.x before 5.4.2 GA may have access to read-write administrators password hashes (not including super-admins) stored on the appliance via the webui REST API, and may therefore be able to crack them.
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Analysis
by VulDB Data Team • 10/05/2022
This vulnerability affects Fortinet devices running specific versions of FortiOS operating system where read-only administrative users can potentially access password hashes of read-write administrators through the web user interface REST API. The flaw exists in the permission model implementation within the FortiOS web interface, allowing unauthorized privilege escalation through credential exposure. This represents a significant security weakness in the principle of least privilege enforcement that should prevent read-only users from accessing administrative credentials.
The technical implementation of this vulnerability stems from inadequate access control mechanisms within the REST API endpoints responsible for user management and authentication data retrieval. The flaw allows authenticated read-only administrators to query administrative user accounts through the web interface API, specifically retrieving password hash values without proper authorization checks. This issue is classified under CWE-284 Access Control, which addresses improper access control mechanisms that allow unauthorized users to access resources they should not be permitted to access.
The operational impact of this vulnerability is substantial as it enables attackers with read-only administrative privileges to escalate their access level within the network infrastructure. Once the password hashes are obtained, attackers can attempt offline password cracking using various techniques including dictionary attacks, brute force methods, or rainbow table lookups. This creates a pathway for lateral movement within the network and potential full system compromise, especially if administrators reuse passwords across multiple systems. The vulnerability affects both FortiOS 5.2.x versions before 5.2.10 GA and 5.4.x versions before 5.4.2 GA, indicating a widespread issue affecting multiple product lines.
Organizations should immediately implement the Fortinet security patches released for this vulnerability, specifically upgrading to FortiOS 5.2.10 GA or 5.4.2 GA versions. Network administrators should also conduct immediate audits of administrative user accounts to ensure no unauthorized read-only users exist with elevated privileges. The remediation process should include disabling unnecessary administrative accounts and implementing stricter access control policies. Additionally, organizations should consider implementing multi-factor authentication for all administrative accounts and regularly rotate administrative passwords to minimize the impact of credential exposure. This vulnerability aligns with ATT&CK technique T1078 Valid Accounts, as it exploits legitimate administrative accounts through improper access controls, and T1110 Brute Force, as the exposed hashes enable offline password cracking attempts.