CVE-2020-15149 in NodeBB
Summary
by MITRE
NodeBB before version 1.14.3 has a bug introduced in version 1.12.2 in the validation logic that makes it possible to change the password of any user on a running NodeBB forum by sending a specially crafted socket.io call to the server. This could lead to a privilege escalation event due via an account takeover. As a workaround you may cherry-pick the following commit from the project's repository to your running instance of NodeBB: 16cee1b03ba3eee177834a1fdac4aa8a12b39d2a. This is fixed in version 1.14.3.
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Analysis
by VulDB Data Team • 11/10/2020
The vulnerability CVE-2020-15149 represents a critical authentication bypass flaw in NodeBB forums that existed from version 1.12.2 through 1.14.2. This issue stems from a fundamental flaw in the password reset validation logic that allows unauthorized users to manipulate socket.io communication to modify any user account's password. The vulnerability specifically affects the server-side validation mechanism that should have enforced proper authentication and authorization checks before permitting password changes. This represents a classic case of insufficient input validation and inadequate access control enforcement that directly undermines the core security model of the forum platform.
The technical exploitation of this vulnerability occurs through the socket.io communication channel that NodeBB uses for real-time interactions between clients and server. An attacker can craft a malicious socket.io message that bypasses the normal validation checks typically required to verify user identity and authorization status. This flaw allows an attacker to send a password change request for any user account without possessing the legitimate credentials or having proper authorization to make such changes. The vulnerability is categorized under CWE-284 Access Control Issues and specifically relates to improper authorization checks in the authentication subsystem.
The operational impact of this vulnerability extends beyond simple account takeover to encompass broader privilege escalation capabilities within the NodeBB environment. Once an attacker successfully exploits this vulnerability, they can gain full control over any user account on the forum, including administrator accounts if they exist. This creates a significant risk for organizations relying on NodeBB for community management, as it allows for complete compromise of user data, forum content manipulation, and potential lateral movement within the network if the forum is integrated with other systems. The attack vector is particularly concerning because it requires no prior authentication or session information from legitimate users, making it a passive attack that can be executed by anyone with access to the forum's socket.io endpoint.
The mitigation strategy for this vulnerability involves upgrading to NodeBB version 1.14.3 or applying the specific patch referenced in the advisory. The recommended cherry-pick commit 16cee1b03ba3eee177834a1fdac4aa8a12b39d2a addresses the root cause by correcting the validation logic that was allowing unauthorized password modifications. Organizations should also implement network-level monitoring to detect unusual socket.io traffic patterns and consider additional security controls such as rate limiting on authentication-related API endpoints. From an ATT&CK perspective, this vulnerability maps to T1078 Valid Accounts and T1566 Phishing, as it enables adversaries to maintain persistent access through compromised credentials and can be exploited as part of broader attack chains involving credential theft and privilege escalation. The vulnerability demonstrates the critical importance of proper access control implementation in web applications and highlights how seemingly minor validation logic flaws can create significant security risks in community forums and social platforms.