CVE-2016-8563 in Automation License Manager
Summary
by MITRE
Siemens Automation License Manager (ALM) before 5.3 SP3 Update 1 allows remote attackers to cause a denial of service (ALM service outage) via crafted packets to TCP port 4410.
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Analysis
by VulDB Data Team • 09/26/2022
The Siemens Automation License Manager (ALM) vulnerability identified as CVE-2016-8563 represents a significant security flaw in industrial automation systems that affects versions prior to 5.3 SP3 Update 1. This vulnerability resides within the network service component of ALM that operates on TCP port 4410, which is a critical port for license management in Siemens' industrial automation environments. The flaw enables remote attackers to disrupt service availability by sending specifically crafted packets to this designated port, effectively creating a denial of service condition that can impact operational technology infrastructure.
The technical implementation of this vulnerability stems from inadequate input validation within the ALM service's packet processing mechanism. When the service receives malformed or specially constructed network packets on TCP port 4410, it fails to properly handle these inputs, leading to service instability and eventual termination of the ALM service. This type of vulnerability falls under CWE-129, Input Validation, and specifically manifests as a lack of proper bounds checking and error handling in network protocol parsing. The flaw demonstrates a classic buffer over-read or improper state handling issue that can be exploited without requiring authentication or specialized privileges, making it particularly dangerous in industrial control environments where availability is paramount.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire industrial automation systems. When the ALM service becomes unavailable, license management functions cease to operate properly, which can lead to unauthorized access to licensed software components or complete loss of licensing functionality. This disruption directly affects the operational technology infrastructure by preventing proper license validation, potentially causing production systems to become non-functional or operate in unauthorized modes. The vulnerability creates a condition where attackers can cause cascading failures in industrial processes that depend on proper licensing and authorization mechanisms, aligning with ATT&CK technique T1499.002 for Network Denial of Service.
Organizations implementing Siemens ALM solutions must prioritize immediate remediation through the application of the 5.3 SP3 Update 1 patch or equivalent security updates. Network segmentation and access control measures should be implemented to restrict access to TCP port 4410 to only authorized systems and personnel. Monitoring for anomalous traffic patterns on this port can help detect exploitation attempts, while regular vulnerability assessments should be conducted to identify similar flaws in industrial control system components. The vulnerability highlights the importance of maintaining up-to-date industrial security solutions and implementing defense-in-depth strategies that protect critical infrastructure from remote exploitation. Additionally, organizations should consider implementing network access controls and intrusion detection systems to monitor for exploitation attempts targeting industrial protocols and services, particularly in environments where operational technology and information technology converge.