CVE-2014-8657 in CG6640E Wireless Gateway
Summary
by MITRE
The Compal Broadband Networks (CBN) CH6640E and CG6640E Wireless Gateway 1.0 with firmware CH6640-3.5.11.7-NOSH allows remote attackers to cause a denial of service (disconnect all wifi clients) via a request to wirelessChannelStatus.html.
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Analysis
by VulDB Data Team • 08/20/2024
The vulnerability identified as CVE-2014-8657 affects Compal Broadband Networks CBN CH6640E and CG6640E Wireless Gateway devices running firmware version 1.0 with specific firmware revision CH6640-3.5.11.7-NOSH. This represents a critical denial of service flaw that specifically targets the wireless networking functionality of these broadband gateways. The vulnerability is particularly concerning as it allows remote attackers to completely disrupt wireless connectivity for all connected clients without requiring any authentication or privileged access. The attack vector is through a simple HTTP request directed to the wirelessChannelStatus.html endpoint, which demonstrates how a seemingly benign web interface can serve as an entry point for significant network disruption. This flaw falls under the category of insufficient input validation and improper error handling within network device management interfaces, creating a pathway for unauthorized network disruption that directly impacts end-user connectivity and service availability.
The technical implementation of this vulnerability stems from the device's failure to properly validate or sanitize input parameters when processing requests to the wirelessChannelStatus.html interface. When a remote attacker sends a specially crafted request to this endpoint, the device's web server fails to properly handle the malformed input, leading to a complete system crash or unexpected behavior that results in disconnection of all wireless clients. This represents a classic buffer overflow or input validation vulnerability that allows an attacker to manipulate the device's internal state through web-based interfaces. The vulnerability is classified as a weakness in the device's web application layer where insufficient validation of user-supplied input leads to system instability and service disruption. The flaw operates at the application layer of the network stack and demonstrates how embedded web interfaces in network equipment can contain security vulnerabilities that are exploitable from remote locations without authentication.
The operational impact of this vulnerability extends beyond simple service disruption as it affects the fundamental connectivity of wireless networks within residential and small business environments. When all wireless clients are disconnected simultaneously, users lose access to internet services, wireless printing, smart home devices, and other network-dependent applications that rely on the affected gateway. This type of attack can be particularly damaging in environments where wireless connectivity is essential for business operations or where users depend on continuous network access for critical communications. The vulnerability affects both CH6640E and CG6640E models, indicating a widespread issue within the product line and suggesting that multiple installations across different geographic regions could be simultaneously compromised. The remote nature of the attack means that adversaries can exploit this vulnerability from anywhere on the internet without requiring physical access or network proximity, making it particularly dangerous for widespread deployment scenarios.
Security mitigation strategies for this vulnerability should include immediate firmware updates from Compal or the device manufacturer to address the input validation flaw in the web interface. Network administrators should also implement network segmentation and access controls to limit exposure of these devices to untrusted networks, particularly by ensuring that management interfaces are not directly accessible from the internet. The implementation of web application firewalls and intrusion prevention systems can help detect and block malicious requests to the vulnerable wirelessChannelStatus.html endpoint. Additionally, network monitoring should be enhanced to detect sudden disconnections of wireless clients that could indicate exploitation of this vulnerability. From a cybersecurity framework perspective, this vulnerability aligns with CWE-20 (Improper Input Validation) and represents a clear violation of the principle of least privilege in network device management interfaces. The attack pattern follows typical denial of service tactics documented in the MITRE ATT&CK framework under the T1499 category for network disruption attacks, where adversaries seek to make network resources unavailable to legitimate users through system or service disruption techniques. Organizations should also consider implementing device hardening procedures that disable unnecessary web management interfaces and restrict access to authorized administrative personnel only.