CVE-2006-6785 in Open Newsletter
Summary
by MITRE
The (1) settings.php and (2) subscribers.php scripts in Open Newsletter 2.5 and earlier do not exit when authentication fails, which allows remote attackers to perform unauthorized administrative actions, or execute arbitrary code in conjunction with another vulnerability.
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Analysis
by VulDB Data Team • 12/21/2024
The vulnerability described in CVE-2006-6785 affects Open Newsletter version 2.5 and earlier, specifically targeting the settings.php and subscribers.php scripts. This represents a critical authentication bypass flaw that fundamentally compromises the security model of the application. The core issue lies in the improper handling of authentication failures within these administrative scripts, where the applications fail to terminate execution when unauthorized access attempts are detected. This design flaw creates a persistent security weakness that can be exploited by remote attackers to gain unauthorized administrative privileges.
From a technical perspective, the vulnerability stems from the absence of proper exit mechanisms when authentication checks fail. According to CWE-284, this manifests as an improper access control vulnerability where the application does not adequately enforce authorization boundaries. The flaw operates at the application logic level, where the scripts continue execution even after detecting failed authentication attempts, allowing attackers to proceed with administrative operations that should be restricted to authorized users only. This behavior creates a pathway for privilege escalation attacks where unauthorized users can manipulate the application's administrative functions.
The operational impact of this vulnerability is severe and multifaceted, potentially enabling remote code execution when combined with other vulnerabilities within the same application. Attackers can leverage this flaw to perform unauthorized administrative actions including but not limited to modifying newsletter configurations, managing subscriber lists, and potentially executing arbitrary code on the server. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and T1548.001 which covers abuse of cloud permissions, as it essentially allows attackers to assume administrative roles without proper authentication. The implications extend beyond simple unauthorized access, potentially allowing for complete system compromise through subsequent exploitation.
The recommended mitigations for this vulnerability involve immediate code-level fixes to ensure proper authentication handling and exit procedures. Developers should implement robust authentication failure mechanisms that terminate script execution upon failed authentication attempts. This includes adding explicit exit statements or return codes when authentication checks fail, ensuring that administrative functions are only accessible to properly authenticated users. Additionally, implementing proper input validation and sanitization measures can help prevent exploitation of this vulnerability when combined with other weaknesses. Organizations should also consider implementing network-level controls such as firewalls and access control lists to limit exposure, while regular security audits and code reviews should be conducted to identify similar authentication bypass vulnerabilities in other application components.