CVE-2020-10045 in SICAM MMU
Summary
by MITRE
A vulnerability has been identified in SICAM MMU (All versions < V2.05), SICAM SGU (All versions), SICAM T (All versions < V2.18). An error in the challenge-response procedure could allow an attacker to replay authentication traffic and gain access to protected areas of the web application.
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Analysis
by VulDB Data Team • 07/15/2020
This vulnerability affects Siemens industrial security products including SICAM MMU, SICAM SGU, and SICAM T devices where the challenge-response authentication mechanism contains a critical flaw that enables unauthorized access. The vulnerability stems from insufficient randomization or prediction of challenge values within the authentication protocol, creating opportunities for attackers to capture and replay authentication exchanges without proper authorization. The flaw specifically impacts versions prior to V2.05 for MMU and V2.18 for T devices, indicating that Siemens has acknowledged and potentially addressed this weakness in later releases. This type of vulnerability represents a fundamental breakdown in the authentication security model where the cryptographic integrity of the challenge-response process is compromised. The issue falls under the category of weak authentication mechanisms that can be exploited through replay attacks, making it particularly dangerous in industrial control environments where unauthorized access could lead to critical system compromise. According to CWE standards, this vulnerability maps to CWE-310 which covers cryptographic weaknesses in authentication protocols, specifically addressing the lack of proper randomization in challenge-response systems. The vulnerability also aligns with ATT&CK technique T1078 which covers valid accounts and legitimate credentials for unauthorized access.
The technical implementation of this flaw allows attackers to intercept legitimate authentication traffic between the client and server components of these security devices. When the challenge-response protocol is executed, the system generates challenge values that should be unpredictable and unique for each authentication attempt. However, the vulnerability enables attackers to predict or regenerate these challenge values, allowing them to replay captured authentication messages and gain unauthorized access to protected web application areas. The replay capability means that an attacker can capture a valid authentication exchange and reuse it multiple times without the need for brute force or other complex attack vectors. This particular weakness undermines the core security principle that authentication should be time-bound and unpredictable, creating persistent access points for malicious actors. The impact is particularly severe because these devices are typically deployed in industrial environments where they control critical infrastructure, making unauthorized access potentially catastrophic.
The operational consequences of this vulnerability extend beyond simple unauthorized access to encompass potential system compromise and operational disruption in industrial control environments. Attackers could gain persistent access to security systems that protect critical infrastructure, potentially allowing them to disable security measures, modify access controls, or even manipulate industrial processes. The vulnerability creates a backdoor that could be exploited for lateral movement within networks, especially in environments where these security devices are integrated with other industrial control systems. Organizations using affected SICAM devices face significant risk of unauthorized access to their industrial security infrastructure, potentially leading to operational technology compromise. The impact is further amplified because these devices are often deployed in environments where security monitoring and incident response capabilities may be limited, making detection of such attacks more challenging. The vulnerability represents a persistent threat that could remain undetected for extended periods, allowing attackers to maintain access and potentially escalate their privileges over time.
Organizations should implement immediate mitigation strategies including updating to the latest firmware versions where available, which Siemens has addressed in their subsequent releases. Network segmentation should be implemented to isolate affected devices from critical operational systems, reducing the potential impact of successful exploitation. Additional security controls such as network access controls, intrusion detection systems, and monitoring of authentication traffic can help detect potential replay attacks. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of affected devices within the network infrastructure. The implementation of strong authentication mechanisms including multi-factor authentication and certificate-based authentication should be considered as additional layers of protection. Security teams should also review and update their incident response procedures to ensure preparedness for potential exploitation of this vulnerability. Organizations should maintain continuous monitoring of their industrial control systems for any unauthorized access attempts and establish clear protocols for responding to suspected security incidents involving authentication bypass vulnerabilities.