CVE-2015-3972 in UMG
Summary
by MITRE
The web interface on Janitza UMG 508, 509, 511, 604, and 605 devices supports only short PIN values for authentication, which makes it easier for remote attackers to obtain access via a brute-force attack.
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Analysis
by VulDB Data Team • 02/23/2018
The vulnerability identified as CVE-2015-3972 affects several Janitza power measurement devices including the UMG 508, 509, 511, 604, and 605 models. These devices feature web interfaces that implement authentication mechanisms relying on short PIN values, creating a significant security weakness that can be exploited by remote attackers. The issue stems from insufficient authentication design where the system does not enforce adequate entropy requirements for PIN validation, making the authentication process susceptible to various attack vectors.
This vulnerability represents a classic implementation of weak authentication mechanisms that aligns with CWE-521 Weak Password Requirements, where the system fails to enforce sufficient complexity or length requirements for authentication credentials. The short PIN limitation directly enables brute-force attacks by reducing the search space available to attackers, making it computationally feasible to exhaustively test possible PIN combinations within a reasonable timeframe. The web interface design does not implement account lockout mechanisms or rate limiting, further exacerbating the vulnerability by allowing unlimited authentication attempts without detection.
The operational impact of this vulnerability is substantial as it allows remote attackers to gain unauthorized access to critical power measurement devices that monitor electrical parameters in industrial and commercial environments. Once compromised, attackers can potentially manipulate device settings, access sensitive operational data, or disrupt power monitoring functions that may be critical for facility management and energy consumption tracking. The vulnerability affects devices that are typically deployed in networked environments where they are accessible from external networks, increasing the attack surface and making exploitation more likely.
Security practitioners should implement immediate mitigations including enforcing strong password policies, implementing account lockout mechanisms, and applying network segmentation to limit access to these devices. The ATT&CK framework categorizes this vulnerability under privilege escalation and credential access techniques, specifically targeting T1110 Brute Force and T1078 Valid Accounts. Organizations should also consider applying firmware updates from Janitza if available, implementing network monitoring to detect unusual authentication patterns, and restricting web interface access to trusted IP addresses only. The vulnerability highlights the importance of proper authentication design principles and demonstrates how seemingly minor implementation flaws can create significant security risks in industrial control systems.