CVE-2014-2252 in SIMATIC S7 Cpu-1211c
Summary
by MITRE
Siemens SIMATIC S7-1200 CPU PLC devices with firmware before 4.0 allow remote attackers to cause a denial of service (defect-mode transition) via crafted PROFINET packets, a different vulnerability than CVE-2014-2253.
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Analysis
by VulDB Data Team • 05/08/2026
The vulnerability identified as CVE-2014-2252 affects Siemens SIMATIC S7-1200 CPU programmable logic controllers running firmware versions prior to 4.0. This represents a critical security flaw within industrial control systems that can be exploited remotely to trigger a denial of service condition. The vulnerability specifically targets the PROFINET communication protocol implementation within these PLC devices, demonstrating the increasing complexity and attack surface of modern industrial automation systems. The affected devices operate within critical infrastructure environments where reliability and continuous operation are paramount, making this vulnerability particularly concerning for operational technology security.
The technical flaw manifests through the improper handling of crafted PROFINET packets that can cause the PLC to transition into a defect mode, effectively rendering the device non-operational. This defect mode transition represents a fundamental failure in the device's protocol stack implementation where malformed or specially constructed network packets can trigger an unintended state change in the PLC's operational behavior. The vulnerability differs from CVE-2014-2253, indicating that multiple related flaws exist within the same product line, suggesting potential systemic issues in the firmware's network protocol handling capabilities. This type of vulnerability falls under CWE-129, which addresses improper handling of input boundaries, and specifically relates to improper input validation in network protocol implementations.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise the availability of critical industrial processes that depend on these PLC devices. When a PLC enters defect mode, it typically cannot execute its programmed control functions, potentially leading to production halts, safety system failures, or other cascading effects within industrial processes. The remote nature of the attack means that threat actors can exploit this vulnerability from outside the operational technology network, potentially from the internet or other network segments. This characteristic aligns with ATT&CK technique T1499.001 for network denial of service attacks, where adversaries target network infrastructure to prevent legitimate use of resources. The vulnerability demonstrates how industrial control systems can be vulnerable to attacks that leverage standard industrial protocols, highlighting the need for robust protocol security in OT environments.
Mitigation strategies for CVE-2014-2252 should focus on firmware updates to version 4.0 or later, which would address the underlying protocol handling issues. Network segmentation and access controls should be implemented to limit exposure of these devices to untrusted networks, while also considering the deployment of network monitoring solutions to detect anomalous PROFINET traffic patterns. Organizations should also conduct comprehensive vulnerability assessments of their industrial control systems to identify similar issues within their operational technology infrastructure. The remediation process requires careful planning due to the critical nature of PLC operations, often necessitating scheduled maintenance windows to apply updates without disrupting production processes. Additionally, implementing network access control lists and firewall rules to restrict PROFINET traffic to authorized sources can provide additional defense in depth. This vulnerability underscores the importance of maintaining current firmware versions in industrial environments and demonstrates how seemingly standard protocol implementations can contain critical security flaws that affect operational continuity.