CVE-2012-6437 in ControlLogix controllers
Summary
by MITRE
The device does not properly authenticate users and the potential exists for a remote user to upload a new firmware image to the Ethernet card, whether it is a corrupt or legitimate firmware image. Successful exploitation of this vulnerability could cause loss of availability, integrity, and confidentiality and a disruption in communications with other connected devices.
Rockwell Automation EtherNet/IP products; 1756-ENBT, 1756-EWEB, 1768-ENBT, and 1768-EWEB communication modules; CompactLogix L32E and L35E controllers; 1788-ENBT FLEXLogix adapter; 1794-AENTR FLEX I/O EtherNet/IP adapter; ControlLogix 18 and earlier; CompactLogix 18 and earlier; GuardLogix 18 and earlier; SoftLogix 18 and earlier; CompactLogix controllers 19 and earlier; SoftLogix controllers 19 and earlier; ControlLogix controllers 20 and earlier; GuardLogix controllers 20 and earlier; and MicroLogix 1100 and 1400
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Analysis
by VulDB Data Team • 06/03/2026
The vulnerability described in CVE-2012-6437 represents a critical security flaw in Rockwell Automation's EtherNet/IP communication products that affects a wide range of industrial control systems including CompactLogix and ControlLogix controllers, various Ethernet communication modules, and FLEX I/O adapters. This weakness stems from inadequate authentication mechanisms during firmware update processes, creating a pathway for remote code execution attacks that could compromise the integrity of critical industrial infrastructure. The affected devices span multiple product lines and firmware versions, indicating a systemic issue rather than an isolated incident that requires comprehensive remediation across industrial control networks.
The technical flaw manifests in the improper authentication of Ethernet firmware updates, specifically allowing attackers to perform what is known as a "Trojan horse update" attack. This vulnerability operates at the firmware level and exploits the lack of proper cryptographic verification or digital signatures during the update process, enabling unauthorized code execution without legitimate authentication credentials. The flaw fundamentally undermines the security model of these industrial devices by permitting remote attackers to inject malicious firmware images that can execute arbitrary code on the target systems. This weakness directly aligns with CWE-327, which addresses the use of weak or broken cryptographic algorithms, and represents a significant deviation from secure coding practices in industrial control systems.
The operational impact of this vulnerability extends far beyond simple network security concerns, as it threatens the integrity and availability of industrial control systems that are critical to manufacturing, process control, and infrastructure operations. Remote code execution capabilities allow attackers to potentially gain complete control over affected controllers, leading to production disruptions, data manipulation, or even physical safety hazards in industrial environments. The vulnerability's reach across multiple controller families and firmware versions means that organizations with diverse industrial control system landscapes face widespread exposure, requiring coordinated remediation efforts across their entire operational technology infrastructure. This type of vulnerability represents a significant threat to industrial cybersecurity and aligns with ATT&CK technique T1547.001 for establishing persistence through legitimate credentials and T1059 for executing malicious code remotely.
Organizations must implement multiple layers of defense to mitigate this vulnerability, beginning with immediate firmware updates from Rockwell Automation to address the authentication weakness. Network segmentation and access controls should be strengthened to limit exposure of these critical devices to untrusted networks, while monitoring systems should be deployed to detect unauthorized firmware update attempts. The remediation process should follow industry best practices for industrial cybersecurity, including the implementation of secure update protocols, network isolation of control systems, and comprehensive vulnerability assessment programs. Additionally, organizations should consider implementing network access control measures and regular security audits to prevent similar vulnerabilities from emerging in their industrial control environments, as this flaw represents a fundamental weakness in the security architecture of these critical systems that requires both immediate patching and long-term architectural improvements to prevent future exploitation attempts.