CVE-2014-3889 in SX-2000WG
Summary
by MITRE
silex SX-2000WG devices with firmware before 1.5.4 allow remote attackers to cause a denial of service (connectivity outage) via crafted data in the Options field of a TCP header, a different vulnerability than CVE-2014-3890.
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Analysis
by VulDB Data Team • 03/11/2019
The CVE-2014-3889 vulnerability affects silex SX-2000WG wireless access points running firmware versions prior to 1.5.4, presenting a significant remote denial of service threat that can disrupt network connectivity for affected devices. This vulnerability specifically targets the processing of TCP header options fields, exploiting a flaw in how the device handles malformed or crafted data within these network protocol elements. The vulnerability represents a distinct issue from CVE-2014-3890, indicating separate attack vectors within the same product line that require different mitigation approaches. The affected devices operate within enterprise and small office networking environments where uninterrupted connectivity is critical for business operations.
The technical flaw manifests when the SX-2000WG device receives TCP packets containing specially crafted data within the Options field of the TCP header. This malformed data triggers an improper handling mechanism within the device's network stack implementation, causing the device to become unresponsive or crash entirely. The vulnerability exploits a weakness in input validation and packet processing routines that fail to properly sanitize or reject malformed TCP options data. This type of vulnerability falls under the CWE-129 category of Improper Validation of Array Index, as the device fails to validate the length and content of TCP options data before processing it. The flaw demonstrates poor defensive programming practices where the device does not implement adequate bounds checking or error handling for network protocol elements.
The operational impact of CVE-2014-3889 extends beyond simple service disruption, as it can cause complete network outages for organizations relying on these wireless access points. When exploited, the vulnerability can render the affected devices completely unreachable, requiring manual intervention for recovery including device rebooting or firmware reinstallation. Network administrators may experience extended downtime during which wireless connectivity is lost, potentially affecting business operations, employee productivity, and customer service delivery. The remote nature of the attack means that threat actors can exploit this vulnerability from outside the network perimeter without requiring physical access or local network credentials, making it particularly dangerous for organizations with limited network security controls. This vulnerability aligns with ATT&CK technique T1499.004 for Network Denial of Service, representing a specific implementation weakness that can be leveraged for service disruption.
Organizations should implement immediate mitigation strategies including firmware updates to version 1.5.4 or later, which contain patches addressing the TCP header processing flaw. Network segmentation and access control measures should be deployed to limit exposure of these devices to untrusted networks, while intrusion detection systems can be configured to monitor for suspicious TCP packet patterns that may indicate exploitation attempts. Device monitoring should include regular checks for connectivity issues or unexpected reboots that could indicate exploitation. The vulnerability highlights the importance of maintaining current firmware versions and implementing network security monitoring to detect and respond to exploitation attempts. Additionally, organizations should consider implementing network access controls that limit which external systems can communicate with these devices, reducing the attack surface available to potential threat actors.