CVE-2018-7241 in Modicon Premium
Summary
by MITRE
Hard coded accounts exist in Schneider Electric's Modicon Premium, Modicon Quantum, Modicon M340, and BMXNOR0200 controlers in all versions of the communication modules.
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Analysis
by VulDB Data Team • 01/27/2020
Schneider Electric's Modicon series of industrial control systems including Premium, Quantum, M340, and BMXNOR0200 controllers contain persistent hard coded accounts that represent a significant security vulnerability affecting all versions of their communication modules. This flaw allows unauthorized access to critical industrial control infrastructure through predetermined credentials that remain unchanged regardless of system configuration or security policies. The vulnerability stems from the inclusion of default usernames and passwords within the firmware that cannot be modified or removed by system administrators, creating a persistent backdoor access vector that undermines the security posture of industrial networks.
The technical implementation of this vulnerability involves embedded credentials stored within the communication module firmware at the hardware level, making it impossible to eliminate through standard configuration changes or software updates. These hard coded accounts typically include default administrative credentials that are well documented within the manufacturer's technical documentation and have been widely shared across security research communities. The flaw manifests as a failure in access control mechanisms where authentication does not properly validate against system-specific credentials, instead allowing immediate access through predetermined account information. This represents a direct violation of security principle 10 from the CWE catalog which addresses the use of hard coded credentials in security-relevant functions.
The operational impact of CVE-2018-7241 extends beyond simple unauthorized access to encompass potential system compromise, data manipulation, and operational disruption within industrial environments. Attackers with knowledge of these default credentials can gain administrative access to critical control systems without requiring additional reconnaissance or exploitation techniques. This vulnerability particularly affects the ATT&CK technique T1078.004 which involves valid accounts with default passwords, allowing adversaries to establish persistence and move laterally within industrial control networks. The presence of these accounts creates a significant risk for industrial control systems as they provide a consistent entry point that remains functional across all system versions and updates.
Mitigation strategies for this vulnerability require immediate administrative action including disabling unused communication modules, implementing network segmentation to isolate industrial control systems from general network access, and deploying network monitoring to detect unauthorized access attempts. System administrators should conduct comprehensive audits of all installed communication modules to identify and disable any that are not actively required for operations. Network administrators should implement strict access controls and authentication mechanisms that do not rely on default credentials, while also ensuring that any communication modules that cannot be physically removed are properly secured through network-level controls. The vulnerability highlights the importance of following security best practices outlined in NIST SP 800-82 for industrial control systems and emphasizes the critical need for secure configuration management throughout the operational lifecycle of industrial equipment. Organizations should also consider implementing intrusion detection systems specifically designed for industrial environments to monitor for suspicious authentication attempts that may indicate exploitation of these hard coded accounts.