CVE-2017-6865 in SIMATIC
Summary
by MITRE
Siemens SIMATIC WinCC (TIA Portal) (V13 all versions before SP2 and V14 before SP1), SIMATIC STEP 7 (TIA Portal) (V13 all versions before SP2 and V14 before SP1), SIMATIC STEP 7 V5.X (All versions), STEP 7 - Micro/WIN SMART (All versions), SMART PC Access V2.0, SIMATIC Automation Tool (All versions), SIMATIC WinCC (All versions), SIMATIC PCS 7 (All versions), SIMATIC NET PC-Software (All versions), Primary Setup Tool (PST) (All versions), Security Configuration Tool (SCT) (All versions), SINEMA Server (All versions), SINAUT ST7CC (All versions), SIMATIC WinAC RTX 2010 SP2 (All versions), SIMATIC WinAC RTX F 2010 SP2 (All versions), SINUMERIK 808D Programming Tool (All versions), SIMATIC WinCC flexible 2008 (All versions) could be affected by a Denial-of-Service condition induced by a specially crafted PROFINET DCP broadcast (Layer 2 - Ethernet) packet.
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Analysis
by VulDB Data Team • 12/06/2022
This vulnerability affects a wide range of Siemens industrial automation software products including WinCC, STEP 7, PCS 7, and various other components within the SIMATIC portfolio. The issue stems from insufficient input validation in the processing of PROFINET Device Configuration Protocol (DCP) broadcast messages at the Ethernet layer 2 level. When a specially crafted DCP broadcast packet is received, the affected systems may experience a denial-of-service condition that disrupts normal operation of the industrial control systems. This represents a critical weakness in the network protocol handling of these automation platforms, as they fail to properly sanitize incoming broadcast traffic that could originate from external sources within the same network segment.
The technical flaw manifests when the affected software components process malformed or specially constructed PROFINET DCP packets that contain unexpected data structures or malformed fields within the DCP message format. These packets, transmitted at the Ethernet layer 2 level, are designed to trigger buffer overflows or other memory corruption conditions within the receiving software components. The vulnerability is particularly concerning because it operates at the network protocol level where industrial control systems often receive broadcast traffic from multiple devices, making it difficult to distinguish between legitimate and malicious packets. This issue aligns with CWE-129, which covers improper validation of the length of input data, and represents a classic example of a buffer overflow vulnerability in industrial protocol processing.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise the integrity of industrial control processes. When affected systems become unresponsive due to the denial-of-service condition, production processes may halt or experience significant delays, leading to financial losses and potential safety issues in critical infrastructure environments. The vulnerability affects multiple generations of Siemens automation software, spanning from legacy V5.X versions through modern TIA Portal releases, indicating a widespread exposure across industrial control system deployments. Attackers could exploit this weakness by simply transmitting a crafted broadcast packet to the network segment, requiring no authentication or specialized access privileges, making it particularly dangerous in operational technology environments where network segmentation may be limited.
Mitigation strategies should focus on network-level protections including implementing proper network segmentation to isolate industrial control systems from general network traffic, deploying network access control lists to filter PROFINET DCP broadcast traffic, and applying firmware updates from Siemens that address the specific vulnerability in affected software versions. Organizations should also consider implementing network monitoring solutions to detect unusual broadcast traffic patterns that could indicate exploitation attempts. The vulnerability demonstrates the importance of network protocol validation in industrial control systems and aligns with ATT&CK technique T1499.001, which covers network disruption through denial-of-service attacks, emphasizing the need for robust input validation in operational technology environments. Given the critical nature of industrial control systems, administrators should prioritize patching affected systems and implementing network-level controls to prevent exploitation of this vulnerability across their operational technology infrastructure.