CVE-2012-6562 in Elgg
Summary
by MITRE
engine/lib/users.php in Elgg before 1.8.5 does not properly specify permissions for the useradd action, which allows remote attackers to create arbitrary accounts.
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Analysis
by VulDB Data Team • 02/27/2019
The vulnerability identified as CVE-2012-6562 affects Elgg versions prior to 1.8.5 and resides within the engine/lib/users.php file. This represents a critical access control flaw that undermines the fundamental security model of the platform by permitting unauthorized remote exploitation. The issue stems from improper permission specification for the useradd action, creating a scenario where malicious actors can bypass legitimate authentication mechanisms and establish accounts without proper authorization. This vulnerability directly impacts the integrity and confidentiality of user data within Elgg installations, as it enables attackers to potentially gain persistent access to systems through unauthorized account creation.
The technical implementation flaw occurs at the application logic level where the useradd action lacks proper authorization checks. According to CWE-284, this constitutes an improper access control vulnerability where the system fails to enforce appropriate security restrictions on user account creation functionality. The vulnerability allows remote attackers to exploit the missing permission validation by sending specially crafted requests that trigger the useradd functionality without requiring valid authentication credentials. This flaw operates at the application layer and can be exploited through network-based attacks, making it particularly dangerous as it does not require local system access or elevated privileges to be successful.
From an operational impact perspective, this vulnerability creates significant risks for organizations using Elgg platforms. Attackers can leverage this weakness to establish persistent user accounts with varying privilege levels, potentially leading to complete system compromise. The vulnerability enables threat actors to perform account takeover attacks, create backdoor access points, and conduct further malicious activities within the compromised environment. According to ATT&CK framework, this vulnerability maps to T1133 - External Remote Services and T1078 - Valid Accounts, as it allows adversaries to establish unauthorized access through legitimate account creation mechanisms. The impact extends beyond immediate account creation to potentially enable lateral movement, data exfiltration, and persistent presence within target networks.
The recommended mitigations for CVE-2012-6562 include immediate patching to Elgg version 1.8.5 or later, which addresses the improper permission handling in the useradd action. Organizations should also implement network-level controls such as firewall rules to restrict access to user management endpoints and employ intrusion detection systems to monitor for suspicious account creation activities. Additionally, administrators should conduct thorough security reviews of all user management functions and ensure proper authentication and authorization mechanisms are in place. The vulnerability highlights the importance of implementing defense-in-depth strategies and maintaining up-to-date security patches as a fundamental security control to prevent exploitation of known vulnerabilities.