CVE-2012-0931 in Modicon Quantum PLC
Summary
by MITRE
Schneider Electric Modicon Quantum PLC does not perform authentication between the Unity software and PLC, which allows remote attackers to cause a denial of service or possibly execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 11/29/2021
The vulnerability identified as CVE-2012-0931 affects Schneider Electric Modicon Quantum programmable logic controllers that operate within industrial control systems and supervisory control and data acquisition environments. This flaw represents a critical security weakness in the communication protocol between the Unity configuration software and the target PLC, where the system fails to implement proper authentication mechanisms. The absence of authentication creates an exploitable condition that allows unauthorized remote access to the industrial control infrastructure. The vulnerability resides in the communication layer of the Modicon Quantum PLC, specifically within the protocol handling that governs how the Unity software establishes connections and exchanges data with the controller. This weakness is particularly concerning in industrial environments where operational technology systems require robust security measures to prevent unauthorized access and potential compromise of critical infrastructure operations.
The technical flaw manifests as a lack of authentication validation between the Unity configuration software and the Modicon Quantum PLC, enabling attackers to establish connections without proper credential verification. This authentication bypass vulnerability allows remote threat actors to manipulate the PLC's operational state through unspecified attack vectors that may include command injection, buffer overflow exploitation, or direct memory manipulation techniques. The vulnerability's impact extends beyond simple denial of service conditions to potentially enable arbitrary code execution within the PLC environment, representing a significant risk to industrial control system integrity. The flaw essentially removes the security boundary that should exist between authorized configuration tools and the target controller, allowing any remote attacker with network access to potentially gain control over the industrial process control functions. This represents a classic weakness in industrial communication protocols where security mechanisms are either absent or insufficiently implemented, creating a pathway for malicious actors to compromise operational technology infrastructure.
The operational impact of this vulnerability poses severe risks to industrial environments that rely on Modicon Quantum PLCs for process control and automation functions. Remote attackers could potentially cause significant disruptions through denial of service attacks that prevent legitimate operators from accessing or configuring the PLC, leading to production downtime and operational failures. More critically, the possibility of arbitrary code execution creates opportunities for attackers to modify control logic, manipulate process variables, or introduce malicious code that could compromise safety systems and lead to hazardous conditions. The vulnerability affects environments where industrial control systems are connected to corporate networks or the internet, creating exposure to remote attack surfaces that may not be properly secured or monitored. Organizations using these PLCs in critical infrastructure applications face potential risks to process safety, production continuity, and overall operational security. The lack of authentication in industrial control systems represents a fundamental security gap that has been documented in various industrial security frameworks and standards.
Mitigation strategies for CVE-2012-0931 should focus on implementing network segmentation and access controls to limit remote access to industrial control systems. Organizations should deploy network firewalls and access control lists to restrict connectivity between the Unity software and PLC devices, ensuring that only authorized personnel can establish connections. The implementation of secure remote access solutions with proper authentication mechanisms should be considered as alternatives to direct network access. Regular security assessments and vulnerability scanning of industrial control systems should be conducted to identify and remediate similar authentication bypass vulnerabilities. System administrators should ensure that PLC firmware is updated with the latest security patches provided by Schneider Electric, while also implementing network monitoring solutions to detect unauthorized access attempts. The vulnerability aligns with CWE-305 authentication bypass weaknesses and represents a significant concern for industrial security practitioners. Organizations should also consider implementing the principles outlined in the NIST Industrial Control Systems Security guidelines, which emphasize the importance of network segmentation and secure configuration management to protect against remote exploitation of industrial control system vulnerabilities. The ATT&CK framework identifies this type of vulnerability as a potential entry point for lateral movement within industrial control environments, making proper network segmentation and access controls essential defensive measures.