CVE-2017-6823 in Fiyo
Summary
by MITRE
Fiyo CMS 2.0.6.1 allows remote authenticated users to gain privileges via a modified level parameter to dapur/ in an app=user&act=edit action.
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Analysis
by VulDB Data Team • 09/01/2025
The vulnerability identified as CVE-2017-6823 represents a critical privilege escalation flaw within Fiyo CMS version 2.0.6.1 that enables authenticated attackers to elevate their access rights without proper authorization. This issue stems from inadequate input validation and insufficient access control mechanisms within the content management system's administrative interface. The vulnerability specifically manifests when users manipulate the level parameter within the dapur/ directory through the app=user&act=edit action, allowing unauthorized privilege elevation.
The technical exploitation of this vulnerability occurs through parameter manipulation within the application's administrative routing system. When an authenticated user accesses the user management functionality with the app=user&act=edit parameters, the system fails to properly validate the level parameter that controls user permissions. This validation gap permits attackers to modify the level parameter to higher privilege levels, effectively bypassing the intended access control restrictions. The flaw constitutes a classic case of insufficient input sanitization and inadequate privilege validation, which aligns with CWE-285 - Improper Authorization and CWE-352 - Cross-Site Request Forgery vulnerabilities.
The operational impact of this privilege escalation vulnerability extends beyond simple access control bypass to potentially compromise the entire content management system. An attacker who successfully exploits this vulnerability can gain administrative privileges, enabling them to modify or delete content, alter user permissions, access sensitive data, and potentially establish persistent backdoors within the system. This type of vulnerability directly violates the principle of least privilege and can lead to complete system compromise. The vulnerability also falls under ATT&CK technique T1078 - Valid Accounts, as it allows attackers to leverage legitimate user credentials to gain elevated access rights.
Mitigation strategies for CVE-2017-6823 should focus on implementing robust input validation and access control measures within the application's administrative components. The primary solution involves strengthening parameter validation within the user management functionality to ensure that level parameters cannot be manipulated by unauthorized users. Implementing proper access control checks that verify user permissions before allowing any privilege modifications is essential. Additionally, developers should implement proper session management and ensure that all administrative actions are properly authenticated and authorized. The vulnerability also highlights the need for regular security testing and code reviews to identify and remediate similar authorization flaws in web applications. Organizations should consider implementing web application firewalls and monitoring for suspicious parameter manipulation attempts to detect potential exploitation attempts.