CVE-2016-0859 in WebAccess
Summary
by MITRE
Integer overflow in the Kernel service in Advantech WebAccess before 8.1 allows remote attackers to execute arbitrary code or cause a denial of service (stack-based buffer overflow) via a crafted RPC request.
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Analysis
by VulDB Data Team • 07/23/2018
The vulnerability identified as CVE-2016-0859 represents a critical integer overflow flaw within the kernel service of Advantech WebAccess software versions prior to 8.1. This vulnerability exists in the remote procedure call handling mechanism and manifests as a stack-based buffer overflow that can be exploited by remote attackers to achieve arbitrary code execution or cause denial of service conditions. The flaw specifically affects the processing of crafted RPC requests that manipulate integer values beyond their intended capacity, creating conditions where subsequent buffer operations can overwrite adjacent memory regions.
The technical implementation of this vulnerability stems from inadequate input validation and integer overflow handling within the kernel service component of Advantech WebAccess. When a malicious RPC request is received, the system processes integer values that should represent buffer sizes or array indices without proper bounds checking. This allows an attacker to craft requests that cause integer overflow conditions, resulting in buffer overflows that can be leveraged to overwrite stack memory. The CWE-190 category classification applies here, as the vulnerability involves integer overflow conditions that lead to buffer overflows through improper handling of integer arithmetic operations.
From an operational perspective, this vulnerability presents significant risks to industrial control systems and SCADA environments where Advantech WebAccess is deployed. The remote exploitation capability means that attackers can target these systems from outside the network perimeter without requiring physical access or prior authentication. The potential for arbitrary code execution allows threat actors to gain full control over affected systems, potentially leading to industrial espionage, operational disruption, or even physical safety hazards in critical infrastructure environments. The denial of service component further compounds the risk by enabling attackers to disrupt operations without necessarily gaining persistent access.
The attack surface for this vulnerability extends across various industrial automation and control systems that rely on Advantech WebAccess for remote monitoring and control functions. Organizations implementing these solutions in manufacturing plants, energy facilities, or other critical infrastructure environments face particular risk due to the potential for cascading failures and operational disruptions. The vulnerability aligns with ATT&CK technique T1210 for exploitation of remote services and T1059 for command and script execution, demonstrating how attackers can leverage this flaw to establish persistent access and execute malicious code within operational technology environments.
Mitigation strategies for CVE-2016-0859 primarily focus on immediate software updates and system hardening measures. Organizations should prioritize upgrading to Advantech WebAccess version 8.1 or later, which contains patches addressing the integer overflow conditions. Network segmentation and access control measures should be implemented to limit exposure of affected systems to untrusted networks. Additionally, monitoring for suspicious RPC traffic patterns and implementing intrusion detection systems can help identify exploitation attempts. The implementation of defense-in-depth strategies including firewall rules restricting RPC access, disabling unnecessary services, and regular security assessments of industrial control systems provides comprehensive protection against this and similar vulnerabilities in operational technology environments.