CVE-2017-2681 in SIMATIC S7-300
Summary
by MITRE
Siemens SIMATIC S7-300 incl. F and T (All versions before V3.X.14), SIMATIC S7-400 incl. F and H (All versions), SIMATIC HMI Comfort Panels, HMI Multi Panels, HMI Mobile Panels (All versions) could be affected by a Denial-of-Service condition induced by a specially crafted PROFINET DCP (Layer 2 - Ethernet) packet sent to an affected product.
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Analysis
by VulDB Data Team • 07/09/2024
The vulnerability identified as CVE-2017-2681 affects critical industrial control systems manufactured by Siemens, specifically targeting their SIMATIC S7-300 and S7-400 series programmable logic controllers along with various HMI panels. This vulnerability represents a significant concern for industrial cybersecurity as it impacts devices that form the backbone of many critical infrastructure operations including manufacturing plants, energy facilities, and process control systems. The affected products operate within operational technology environments where reliability and continuous operation are paramount, making any potential denial-of-service condition particularly dangerous. The vulnerability stems from insufficient input validation within the PROFINET DCP (Device Configuration Protocol) implementation, which operates at the data link layer of the OSI model.
The technical flaw manifests when an attacker sends a specially crafted PROFINET DCP packet over Ethernet to an affected Siemens device. This packet contains malformed or unexpected data that the device's network stack fails to properly handle, leading to a system crash or restart. The vulnerability is particularly concerning because PROFINET DCP is a standard protocol used for device discovery and configuration in industrial networks, making it a legitimate and frequently used communication mechanism. The attack requires only network access to the affected device and does not require authentication, making it accessible to attackers with minimal privileges. The protocol operates at layer 2 of the network stack, which means the attack can potentially be executed from any location on the same network segment, including from outside the industrial network perimeter if network segmentation is inadequate.
The operational impact of this vulnerability extends beyond simple service disruption as it can compromise the availability of critical industrial processes. When affected devices experience denial-of-service conditions, production lines may halt, safety systems may become unavailable, and process control may be interrupted, potentially leading to financial losses, safety hazards, or environmental impacts. The vulnerability affects multiple product lines including S7-300 with F and T modules, S7-400 with F and H modules, and various HMI panels, creating widespread exposure across industrial control networks. The fact that this vulnerability affects all versions of the S7-400 series and all versions of the HMI panels indicates a fundamental flaw in the protocol implementation that was not adequately addressed through version updates, suggesting a systemic issue in the device firmware design.
Organizations affected by CVE-2017-2681 should implement immediate mitigation strategies including network segmentation to isolate critical industrial control systems from general network access, implementing network access controls to restrict PROFINET DCP traffic, and applying official patches provided by Siemens. The vulnerability aligns with CWE-129 which describes improper validation of input boundaries, and can be mapped to ATT&CK technique T1499.002 which covers network denial of service attacks. Network administrators should also consider implementing intrusion detection systems capable of identifying malformed PROFINET DCP packets and monitoring for unusual restart patterns in industrial control devices. The vulnerability demonstrates the importance of secure protocol implementation in industrial environments and highlights the need for comprehensive cybersecurity assessments of operational technology infrastructure. Organizations must also consider the broader implications of this vulnerability within their overall security posture, as it represents a potential entry point for more sophisticated attacks that could compromise the integrity and availability of critical industrial processes.