CVE-2018-14008 in EOS
Summary
by MITRE
Arista EOS through 4.21.0F allows a crash because 802.1x authentication is mishandled.
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Analysis
by VulDB Data Team • 08/09/2024
The vulnerability identified as CVE-2018-14008 affects Arista Enterprise Operating System versions through 4.21.0F and represents a critical flaw in the handling of 802.1x authentication protocols. This issue manifests as a system crash that occurs when the network switch processes 802.1x authentication requests, fundamentally undermining the reliability and availability of network infrastructure. The vulnerability specifically targets the authentication mechanism that governs network access control, where legitimate authentication flows trigger unexpected system behavior leading to complete service disruption.
The technical root cause of this vulnerability lies in improper error handling within the 802.1x authentication subsystem of Arista EOS. When the system receives malformed or unexpected 802.1x packets, particularly during the authentication negotiation phase, the software fails to properly validate input parameters and gracefully handle exceptional conditions. This lack of proper input validation and error recovery mechanisms creates a condition where the system becomes unstable and eventually crashes. The flaw essentially allows an attacker to craft specific 802.1x packets that when processed by the switch cause a denial of service condition through system termination.
From an operational perspective, this vulnerability presents a significant risk to network availability and business continuity. Network switches running affected Arista EOS versions become susceptible to remote denial of service attacks that can be executed by any individual capable of sending 802.1x packets to the switch. The impact extends beyond simple service interruption as network access control mechanisms fail, potentially leaving network segments vulnerable to unauthorized access while the switch remains offline. This vulnerability directly maps to CWE-248, an unspecified flaw in the software that allows for an exception to be thrown without proper handling, and aligns with ATT&CK technique T1499.004 for network disruption through denial of service attacks.
The attack surface for this vulnerability includes any network environment utilizing Arista switches with 802.1x authentication enabled, particularly those in enterprise networks where network access control is critical for security posture. Organizations that rely on 802.1x for wireless network access, wired network authentication, or network segmentation are at particular risk. The vulnerability can be exploited through network-based attacks without requiring authentication or elevated privileges, making it particularly dangerous in environments where network monitoring and access control are essential for maintaining security boundaries. The lack of proper input validation and error handling creates a persistent threat vector that can be repeatedly exploited to maintain network disruption.
Mitigation strategies for CVE-2018-14008 primarily involve applying vendor-supplied patches and firmware updates that address the specific 802.1x authentication handling issues. Organizations should also implement network segmentation and access control measures to limit exposure of affected switches to untrusted network segments. Monitoring for unusual 802.1x traffic patterns and implementing intrusion detection systems that can identify malformed authentication packets provides additional defense layers. Network administrators should consider temporarily disabling 802.1x authentication on affected switches until patches are applied, though this creates temporary security gaps that must be carefully managed. The vulnerability highlights the importance of proper exception handling and input validation in network infrastructure software, aligning with security best practices outlined in NIST SP 800-53 and ISO 27001 frameworks for secure network design and implementation.