CVE-2016-6894 in EOS
Summary
by MITRE
Arista EOS 4.15 before 4.15.8M, 4.16 before 4.16.7M, and 4.17 before 4.17.0F on DCS-7050 series devices allow remote attackers to cause a denial of service (device reboot) by sending crafted packets to the control plane.
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Analysis
by VulDB Data Team • 01/05/2017
The vulnerability identified as CVE-2016-6894 represents a critical denial of service flaw affecting Arista EOS software versions across multiple release branches including 4.15 before 4.15.8M, 4.16 before 4.16.7M, and 4.17 before 4.17.0F. This issue specifically targets DCS-7050 series network devices, which are enterprise-grade switches commonly deployed in data center environments and service provider networks. The vulnerability exists within the control plane processing mechanisms of these devices, making it particularly dangerous as it can be exploited remotely without requiring authentication or physical access to the network infrastructure.
The technical flaw manifests when the device receives crafted packets that trigger improper handling within the control plane software components. These malicious packets are specifically designed to exploit buffer overflow conditions or memory corruption vulnerabilities in the packet processing routines that handle incoming network traffic destined for the device's control plane. The control plane in network switches is responsible for managing routing protocols, spanning tree operations, and other critical network management functions, making it a prime target for attackers seeking to disrupt network operations. When the vulnerable device processes these crafted packets, the malformed data causes the system to crash and subsequently reboot, leading to complete service disruption for the affected network segment.
The operational impact of this vulnerability extends far beyond simple service interruption as it can result in significant network downtime and potential cascading failures within larger network topologies. In data center environments where Arista switches serve as core infrastructure components, a successful exploitation could lead to complete network partitioning, affecting thousands of connected devices and applications that depend on uninterrupted network connectivity. The remote nature of the attack means that threat actors can exploit this vulnerability from anywhere on the internet, making it particularly dangerous for organizations that do not properly segment their network infrastructure or implement adequate monitoring controls. Network administrators may not immediately detect such attacks as the device reboots and returns to normal operation, potentially allowing continued exploitation without detection.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how control plane vulnerabilities can be leveraged for denial of service attacks. The ATT&CK framework categorizes this type of exploitation under T1499.004, specifically targeting network denial of service through manipulation of network infrastructure. Organizations should implement immediate mitigations including applying the vendor-provided patches and updates that address this vulnerability, as well as implementing network segmentation strategies to limit the potential impact of such attacks. Additionally, deploying intrusion detection systems that can identify and alert on suspicious packet patterns targeting control plane interfaces would provide valuable monitoring capabilities. Network administrators should also consider implementing rate limiting and access control lists to reduce the attack surface and prevent unauthorized access to critical network management interfaces.