CVE-2016-0857 in WebAccess
Summary
by MITRE
Multiple heap-based buffer overflows in Advantech WebAccess before 8.1 allow remote attackers to execute arbitrary code via unspecified vectors.
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Analysis
by VulDB Data Team • 07/23/2018
The vulnerability identified as CVE-2016-0857 represents a critical heap-based buffer overflow issue affecting Advantech WebAccess software versions prior to 8.1. This flaw exists within the software's memory management mechanisms and specifically targets heap memory structures that are dynamically allocated during runtime. The vulnerability enables remote attackers to exploit memory corruption patterns that can be leveraged to achieve arbitrary code execution on affected systems. The unspecified vectors suggest that multiple attack pathways may exist within the software's codebase, making the vulnerability particularly concerning from a security perspective as it could be triggered through various input methods or network interactions.
The technical implementation of this vulnerability stems from improper bounds checking within the heap memory allocation routines of Advantech WebAccess. When processing certain input data, the application fails to validate the size of incoming data against the allocated buffer space, creating conditions where maliciously crafted input can overwrite adjacent memory locations. This heap-based overflow allows attackers to manipulate memory contents in ways that can redirect program execution flow, potentially leading to complete system compromise. The vulnerability's classification as heap-based indicates that the memory corruption occurs in the heap segment rather than stack memory, which typically requires more sophisticated exploitation techniques but can be equally devastating.
From an operational standpoint, the impact of CVE-2016-0857 is severe as it enables remote code execution without requiring authentication, making it particularly dangerous for industrial control systems and SCADA environments where Advantech WebAccess is commonly deployed. The vulnerability affects systems that rely on web-based interfaces for monitoring and control operations, potentially allowing attackers to gain persistent access to critical infrastructure. The remote exploitation capability means that attackers can target these systems from outside the network perimeter, significantly expanding the attack surface. This vulnerability directly relates to CWE-122, which describes heap-based buffer overflow conditions, and aligns with ATT&CK technique T1203 for exploitation of remote services and T1059 for execution through command and scripting interpreters.
The exploitation of this vulnerability typically involves crafting malicious input that exceeds the allocated buffer size, causing data to overwrite adjacent heap memory regions. Attackers may leverage this to inject and execute malicious code, potentially leading to privilege escalation, data exfiltration, or system disruption. The lack of specific vector details in the original description suggests that multiple code paths within the application may be susceptible to this type of memory corruption, making comprehensive patching essential. Organizations using Advantech WebAccess should prioritize immediate remediation through the official 8.1 update release, which addresses the underlying memory management flaws. Additional mitigations include network segmentation, firewall rule implementation to restrict access to affected services, and monitoring for anomalous network traffic patterns that may indicate exploitation attempts. The vulnerability underscores the importance of regular security updates in industrial environments where legacy systems may contain unpatched security flaws.