CVE-2016-0860 in WebAccess
Summary
by MITRE
Buffer overflow in the BwpAlarm subsystem in Advantech WebAccess before 8.1 allows remote attackers to cause a denial of service via a crafted RPC request.
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Analysis
by VulDB Data Team • 07/23/2018
The vulnerability identified as CVE-2016-0860 represents a critical buffer overflow condition within the BwpAlarm subsystem of Advantech WebAccess software versions prior to 8.1. This flaw resides in the remote procedure call processing mechanism that handles alarm notifications and system events within industrial automation environments. The buffer overflow occurs when the system receives malformed RPC requests designed to exceed the allocated memory buffer boundaries, potentially leading to arbitrary code execution or system instability. The vulnerability specifically impacts organizations utilizing Advantech WebAccess for industrial control systems where remote monitoring and alarm management are critical functions. The affected subsystem processes incoming alarm data through RPC communications, making it susceptible to exploitation by attackers who can craft malicious requests to trigger the overflow condition.
The technical implementation of this vulnerability stems from inadequate input validation and memory management within the BwpAlarm subsystem's RPC handler. When processing incoming requests, the system fails to properly validate the length and content of data structures before copying them into fixed-size buffers. This classic buffer overflow scenario allows attackers to overwrite adjacent memory locations, potentially corrupting program execution flow or injecting malicious code. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, where insufficient bounds checking permits data to overflow into adjacent memory segments. The attack vector requires network connectivity to the target system and involves sending specially crafted RPC requests that exceed buffer capacity, typically through malformed alarm data or command sequences. The exploitability of this vulnerability is enhanced by the fact that it operates at the application layer without requiring authentication, making it particularly dangerous in industrial environments where network accessibility may be limited but still present.
The operational impact of CVE-2016-0860 extends beyond simple denial of service to potentially compromise entire industrial control systems. Remote attackers can leverage this vulnerability to cause persistent system outages, disrupt critical manufacturing processes, or gain unauthorized access to operational data. The consequences are particularly severe in environments where WebAccess serves as a central monitoring platform for critical infrastructure, such as power generation, water treatment, or chemical processing facilities. The vulnerability can be exploited to create persistent denial of service conditions that may require system restarts or manual intervention to resolve. In industrial settings, this could result in production downtime, safety system failures, or regulatory compliance violations. The attack may also serve as a stepping stone for more sophisticated attacks, potentially allowing threat actors to establish persistent access within industrial networks. According to ATT&CK framework, this vulnerability maps to T1499.004 for network denial of service and T1566.001 for spearphishing through social engineering, though the direct exploitation requires network-based attack vectors.
Mitigation strategies for CVE-2016-0860 focus primarily on software updates and network security controls. Organizations should immediately upgrade to Advantech WebAccess version 8.1 or later, which contains patches addressing the buffer overflow condition. Network segmentation and access controls should be implemented to limit exposure of affected systems to untrusted networks, reducing the attack surface for remote exploitation attempts. Firewall rules should be configured to restrict RPC communication ports and implement rate limiting to detect abnormal request patterns. Regular security assessments and vulnerability scanning should be conducted to identify other potentially affected systems within industrial networks. System monitoring should include detection of unusual RPC traffic patterns or repeated connection attempts that may indicate exploitation attempts. Additionally, organizations should implement network intrusion detection systems capable of identifying malformed RPC requests that could indicate exploitation of this vulnerability. The remediation process should include comprehensive testing of updated systems to ensure that the patch does not introduce compatibility issues with existing industrial control processes or legacy equipment. Regular security updates and patch management procedures should be established to maintain protection against similar vulnerabilities in industrial control system environments.