CVE-2018-4858 in IEC 61850
Summary
by MITRE
A vulnerability has been identified in IEC 61850 system configurator (All versions < V5.80), DIGSI 5 (affected as IEC 61850 system configurator is incorporated) (All versions < V7.80), DIGSI 4 (All versions), SICAM PAS/PQS (All versions < V8.11), SICAM PQ Analyzer (All versions < V3.11), SICAM SCC (All versions). A service of the affected products listening on all of the host's network interfaces on either port 4884/TCP, 5885/TCP, or port 5886/TCP could allow an attacker to either exfiltrate limited data from the system or to execute code with Microsoft Windows user permissions. Successful exploitation requires an attacker to be able to send a specially crafted network request to the vulnerable service and a user interacting with the service's client application on the host. In order to execute arbitrary code with Microsoft Windows user permissions, an attacker must be able to plant the code in advance on the host by other means. The vulnerability has limited impact to confidentiality and integrity of the affected system. At the time of advisory publication no public exploitation of this security vulnerability was known. Siemens confirms the security vulnerability and provides mitigations to resolve the security issue.
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Analysis
by VulDB Data Team • 04/05/2023
This vulnerability resides within industrial control systems and automation software products developed by Siemens, specifically targeting IEC 61850 system configurator implementations across multiple software platforms including DIGSI 4, DIGSI 5, SICAM PAS/PQS, SICAM PQ Analyzer, and SICAM SCC. The flaw manifests in network services that operate on standard TCP ports 4884, 5885, and 5886, all of which are configured to listen on all network interfaces of affected hosts. This design creates an attack surface where unauthorized network access can be exploited without requiring authentication, as these services are inherently exposed to external networks. The vulnerability has been classified under CWE-200 for exposure of sensitive information and CWE-121 for buffer overflow conditions, representing a fundamental weakness in input validation and memory management within the affected software implementations. The attack vector requires a remote network-based approach where an attacker can send specially crafted requests to the vulnerable ports, making this particularly concerning for industrial environments where network segmentation may be inadequate.
The technical exploitation of this vulnerability presents a dual threat landscape involving both data exfiltration and code execution capabilities, though with significant operational prerequisites. The system can potentially allow an attacker to extract limited data from the host system, though the exact nature of this data remains unspecified in the advisory. More critically, code execution is possible but requires pre-existing access to plant malicious code on the target host through alternative means, indicating this represents a privilege escalation vulnerability rather than a direct remote code execution vector. The requirement for user interaction with client applications on the host system suggests that this vulnerability is particularly dangerous in environments where users have elevated privileges or where social engineering attacks could be effective. The exploitation process typically follows the ATT&CK technique T1203 for exploitation for execution, where attackers leverage existing network services to gain system access. The limited impact to confidentiality and integrity suggests that while data leakage is possible, the vulnerability does not enable complete system compromise or data corruption, though this remains a significant concern in industrial control environments where system integrity is paramount.
The operational impact of this vulnerability extends beyond simple network exposure, particularly within industrial environments where these systems are deployed for critical infrastructure operations. These products are commonly used in power generation, transmission, and distribution systems where IEC 61850 standards govern communication protocols between protective relays, control systems, and monitoring applications. The vulnerability creates a persistent risk where attackers could potentially disrupt operations through data exfiltration or system compromise, especially if the affected systems are connected to operational technology networks without proper segmentation. Organizations deploying these software solutions face challenges in assessing risk exposure, as the vulnerability affects multiple product lines and versions, requiring comprehensive inventory management and patching strategies. The lack of known public exploitation at the time of advisory publication does not diminish the severity, as the vulnerability represents a significant attack surface that could be leveraged by sophisticated threat actors. The vulnerability's presence in multiple Siemens products suggests that industrial organizations may have multiple points of exposure across their network infrastructure, particularly in environments where these systems are integrated with broader enterprise networks.
Mitigation strategies for this vulnerability require a multi-layered approach combining network security controls, system hardening, and operational procedures. The primary recommendation involves implementing network segmentation to isolate affected systems from general network access, particularly by blocking access to the vulnerable TCP ports 4884, 5885, and 5886 from external networks. Network access control lists and firewalls should be configured to restrict these ports to only trusted internal network segments where necessary. System administrators should immediately apply available patches from Siemens to upgrade affected products to versions V5.80 or higher for IEC 61850 system configurator, V7.80 or higher for DIGSI 5, and appropriate versions for other affected products. Additionally, implementing network monitoring and intrusion detection systems can help detect suspicious network activity targeting these vulnerable ports. The vulnerability's nature as a service-based attack vector makes endpoint protection and user privilege management critical components of the overall security posture. Organizations should also conduct comprehensive risk assessments to identify all instances of affected software within their industrial control networks and develop incident response procedures specifically addressing potential exploitation of this vulnerability. Regular security audits and penetration testing should be conducted to verify that network controls remain effective and that no new attack vectors have emerged through system modifications or integrations.