CVE-2016-3950 in AR3200
Summary
by MITRE
Huawei AR3200 routers with software before V200R006C10SPC300 allow remote authenticated users to cause a denial of service (restart) via crafted packets.
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Analysis
by VulDB Data Team • 07/25/2022
The Huawei AR3200 series routers represent a significant portion of enterprise networking infrastructure, particularly in medium to large organizations requiring robust routing capabilities. These devices operate as core network components managing traffic flow between different network segments and often serve as gateways for internet connectivity. The vulnerability identified as CVE-2016-3950 specifically affects firmware versions prior to V200R006C10SPC300, indicating a software flaw that has persisted across multiple iterations of the router's operating system. This issue manifests as a remote authenticated denial of service condition, meaning that an attacker who has already established legitimate network credentials can exploit this weakness to disrupt service availability.
The technical mechanism underlying this vulnerability involves the improper handling of crafted network packets within the router's processing pipeline. When authenticated users send specially constructed packets to the affected Huawei AR3200 devices, the system's packet processing routines fail to properly validate or sanitize the incoming data. This processing failure triggers an unexpected system state that results in the automatic restart of the router service. The flaw likely resides in the router's network protocol stack implementation where insufficient input validation occurs during packet parsing, particularly in areas handling routing protocols or network management functions. According to CWE classification, this vulnerability aligns with CWE-129 Input Validation and CWE-20 General Input Validation, as it demonstrates inadequate validation of network packet data that leads to system instability.
The operational impact of this vulnerability extends beyond simple service disruption, creating significant security implications for organizations relying on these network devices. A successful exploitation can result in unauthorized network downtime, potentially affecting business continuity and communication services across the enterprise. The authenticated nature of the attack means that the threat actor must already possess valid credentials, but this requirement does not significantly reduce the risk as compromised accounts represent common attack vectors in enterprise environments. Network administrators may experience service interruptions during critical business hours, potentially leading to financial losses and operational delays. The vulnerability also creates opportunities for more sophisticated attacks where the denial of service serves as a precursor to other malicious activities, such as network reconnaissance or privilege escalation attempts.
Mitigation strategies for CVE-2016-3950 primarily focus on firmware updates and network access controls. Organizations should immediately upgrade their Huawei AR3200 routers to firmware version V200R006C10SPC300 or later, which contains the necessary patches to address the packet validation issues. Network segmentation and access control measures should be implemented to limit the number of authenticated users who can send packets to critical routing infrastructure. The implementation of network monitoring systems can help detect unusual packet patterns that may indicate exploitation attempts. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 Network Denial of Service and T1566.002 Phishing via Service, as it represents a service disruption attack that can be initiated through network-based phishing campaigns. Additionally, implementing network access control lists and restricting administrative access to routing protocols can provide additional defense-in-depth measures. Regular vulnerability assessments and penetration testing should be conducted to identify similar issues in other network infrastructure components, as this vulnerability type often indicates broader protocol implementation weaknesses that may affect other network devices within the same organization.