Source: ics-cert@hq.dhs.gov
The Central application in i-GEN opLYNX before 2.01.9 allows remote attackers to bypass authentication via vectors involving the disabling of browser JavaScript support.
i-GEN opLYNX versions prior to 2.01.9 are vulnerable to a critical authentication bypass, allowing unauthorized remote access. This vulnerability leverages the disabling of JavaScript in the user's browser to circumvent security controls, potentially leading to complete system compromise and data exfiltration.
Step 1: Target Identification: The attacker identifies a target system running i-GEN opLYNX before version 2.01.9.
Step 2: JavaScript Disablement: The attacker disables JavaScript in their web browser settings.
Step 3: Authentication Request: The attacker attempts to access a protected resource within the i-GEN opLYNX Central application, such as the login page or a restricted area.
Step 4: Client-Side Bypass: The attacker's browser, with JavaScript disabled, bypasses the client-side authentication checks that would normally prevent access.
Step 5: Server-Side Weakness: The server-side authentication logic fails to adequately validate the user's identity, allowing the request to proceed.
Step 6: Unauthorized Access: The attacker gains unauthorized access to the i-GEN opLYNX Central application, potentially accessing sensitive data or performing administrative actions.
The vulnerability stems from a flawed authentication mechanism in i-GEN opLYNX's Central application. The application relies on client-side JavaScript for authentication validation. By disabling JavaScript in the browser, an attacker can bypass these client-side checks. The server-side authentication logic fails to adequately validate the user's identity, allowing unauthorized access. The root cause is a lack of server-side authentication enforcement, relying solely on client-side validation, which is easily circumvented. This is a design flaw, not a specific code-level vulnerability like a buffer overflow or SQL injection.
While no specific APTs are directly linked to this vulnerability, it's a prime target for opportunistic attackers and could be leveraged by any threat actor seeking initial access. This vulnerability is not listed on the CISA KEV.
Monitor web server logs for unusual access patterns, such as requests from IP addresses without prior authentication attempts.
Analyze HTTP request headers for evidence of JavaScript being disabled (e.g., User-Agent strings).
Implement network intrusion detection systems (IDS) with rules to identify requests bypassing JavaScript-based authentication.
Review application logs for failed login attempts followed by successful access from the same IP address.
Monitor for changes in user privileges or data access patterns that deviate from normal behavior.
Upgrade to i-GEN opLYNX version 2.01.9 or later.
Implement robust server-side authentication and authorization mechanisms that do not rely solely on client-side validation.
Enforce strong password policies and multi-factor authentication (MFA).
Regularly audit user accounts and permissions.
Implement a web application firewall (WAF) to filter malicious traffic.
Educate users about the risks of disabling JavaScript and the importance of using up-to-date browsers.