CVE-2018-7240 in Modicon Quantum
Summary
by MITRE
A vulnerability exists in Schneider Electric's Modicon Quantum in all versions of the communication modules which could allow arbitrary code execution. An FTP command used to upgrade the firmware of the module can be misused to cause a denial of service, or in extreme cases, to load a malicious firmware.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 01/27/2020
The vulnerability identified as CVE-2018-7240 affects Schneider Electric's Modicon Quantum communication modules across all firmware versions, representing a critical security flaw that undermines the integrity and availability of industrial control systems. This vulnerability specifically targets the firmware upgrade mechanism through FTP commands, which are designed to facilitate legitimate software updates but can be exploited by malicious actors to compromise system functionality. The flaw resides in the improper validation and handling of FTP commands during the firmware upgrade process, creating an attack surface that allows unauthorized code execution.
The technical implementation of this vulnerability stems from insufficient input validation within the firmware upgrade functionality of the Modicon Quantum modules. When the system processes FTP commands for firmware updates, it fails to properly sanitize or verify the commands received from remote sources, enabling attackers to inject malicious payloads or manipulate the upgrade process. This weakness directly maps to CWE-77: Improper Neutralization of Special Elements used in a Command, which describes how command injection vulnerabilities occur when untrusted data is incorporated into system commands without proper validation. The vulnerability allows an attacker to either execute arbitrary code on the device or cause a denial of service condition, effectively compromising the operational integrity of the industrial control system.
The operational impact of CVE-2018-7240 extends beyond simple system compromise, as it creates persistent threats to industrial infrastructure security and can lead to significant operational disruptions. Attackers who successfully exploit this vulnerability can gain persistent access to the communication modules, potentially enabling them to manipulate industrial processes, disrupt production flows, or serve as a foothold for broader attacks within the industrial control network. The ability to load malicious firmware represents a particularly dangerous aspect of this vulnerability, as it allows attackers to fundamentally alter the behavior of critical control systems. This type of attack aligns with ATT&CK technique T1059.005: Command and Scripting Interpreter: Visual Basic, which describes how adversaries can use command execution capabilities to establish persistence and maintain control over compromised systems.
Organizations utilizing Schneider Electric Modicon Quantum modules must implement immediate mitigations to address this vulnerability, including network segmentation to isolate critical control systems from general network access, implementing strict firewall rules to restrict FTP traffic to authorized sources only, and conducting thorough network monitoring to detect anomalous firmware upgrade activities. The vulnerability also requires careful attention to access controls and authentication mechanisms, as the exploitation typically requires some level of network access to the communication modules. Regular firmware updates from Schneider Electric should be prioritized, though organizations must verify that the updated firmware versions properly address this specific vulnerability. Additionally, implementing network intrusion detection systems capable of identifying suspicious FTP command sequences and monitoring for unauthorized firmware modification attempts can provide early warning capabilities. The remediation process should include comprehensive testing of updated firmware to ensure that the vulnerability is properly addressed without introducing compatibility issues with existing industrial processes.