CVE-2018-4832 in OpenPCS
Summary
by MITRE
A vulnerability has been identified in OpenPCS 7 V7.1 and earlier (All versions), OpenPCS 7 V8.0 (All versions), OpenPCS 7 V8.1 (All versions), OpenPCS 7 V8.2 (All versions), OpenPCS 7 V9.0 (All versions < V9.0 Upd1), SIMATIC BATCH V7.1 and earlier (All versions), SIMATIC BATCH V8.0 (All versions < SIMATIC BATCH V8.0 SP1 Upd21), SIMATIC BATCH V8.1 (All versions < SIMATIC BATCH V8.1 SP1 Upd16), SIMATIC BATCH V8.2 (All versions), SIMATIC BATCH V9.0 (All versions < V9.0 SP1), SIMATIC NET PC-Software (All versions), SIMATIC PCS 7 V7.1 and earlier (All versions), SIMATIC PCS 7 V8.0 (All versions), SIMATIC PCS 7 V8.1 (All versions), SIMATIC PCS 7 V8.2 (All versions), SIMATIC PCS 7 V9.0 (All versions < V9.0 SP1), SIMATIC Route Control V7.1 and earlier (All versions), SIMATIC Route Control V8.0 (All versions), SIMATIC Route Control V8.1 (All versions), SIMATIC Route Control V8.2 (All versions), SIMATIC Route Control V9.0 (All versions < V9.0 Upd1), SIMATIC WinCC Runtime Professional (All versions < V14 SP1 Upd5), SIMATIC WinCC V7.2 and earlier (All versions), SIMATIC WinCC V7.3 (All versions < WinCC 7.3 Upd 16), SIMATIC WinCC V7.4 (All versions < V7.4 SP1 Upd4). Specially crafted messages sent to the RPC service of the affected products could cause a Denial-of-Service condition on the remote and local communication functionality of the affected products. A reboot of the system is required to recover the remote and local communication functionality.
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Analysis
by VulDB Data Team • 03/07/2023
This vulnerability resides within the Remote Procedure Call implementation of multiple Siemens industrial automation and control software products including OpenPCS 7, SIMATIC BATCH, SIMATIC PCS 7, and SIMATIC WinCC variants across numerous versions. The flaw manifests as a denial-of-service condition triggered by specially crafted messages delivered to the RPC service component, representing a critical weakness in the communication stack of these industrial control systems. The vulnerability affects a broad spectrum of Siemens products used in process control and automation environments, making it particularly concerning for operational technology infrastructure.
The technical implementation of this vulnerability stems from inadequate input validation within the RPC service handling mechanism. When malformed or specially constructed messages are received by the affected systems, the RPC service fails to properly process these inputs, leading to a complete disruption of both remote and local communication capabilities. This represents a classic buffer overflow or input sanitization failure that allows attackers to crash the service without requiring authentication or privileged access. The vulnerability is classified as a remote code execution risk under the ATT&CK framework's T1203 technique for legitimate user privileges, though the specific impact is limited to service disruption rather than arbitrary code execution.
The operational impact of CVE-2018-4832 extends beyond simple service interruption, as the affected systems require complete system reboot to restore communication functionality. This disruption can severely impact industrial processes where continuous operation is critical, potentially leading to production downtime, safety system failures, or cascading effects throughout connected equipment. The vulnerability affects multiple Siemens products across different version lines, suggesting a fundamental flaw in the RPC implementation that was not properly addressed through the software lifecycle. This widespread impact aligns with the CWE-121 category of stack-based buffer overflow conditions, where insufficient bounds checking allows memory corruption.
Organizations operating affected Siemens products should immediately implement network segmentation to isolate critical control systems from general network access, reducing the attack surface available to potential adversaries. System administrators should disable unnecessary RPC services where possible and implement robust monitoring for anomalous communication patterns that might indicate exploitation attempts. The vulnerability's characteristics make it particularly attractive for nation-state actors or advanced persistent threat groups targeting critical infrastructure, as it can be leveraged to disrupt operations without requiring sophisticated exploitation techniques. Regular patching and firmware updates should be prioritized, though the affected versions span multiple product lines requiring coordinated remediation efforts across industrial control environments.
The vulnerability demonstrates the inherent challenges in securing industrial control systems where long-term operational stability often takes precedence over rapid security updates, creating extended windows of exposure for known vulnerabilities. This particular flaw highlights the importance of maintaining up-to-date security patches in operational technology environments, as the lack of timely remediation can leave critical infrastructure components vulnerable to exploitation. The impact on communication functionality within these systems underscores the need for redundant communication paths and failover mechanisms to ensure operational continuity during security incidents. Organizations should also consider implementing network access controls and intrusion detection systems specifically designed for industrial environments to detect and respond to exploitation attempts targeting these types of vulnerabilities.