CVE-2016-4824 in CG-WLR300GNV
Summary
by MITRE
The Wi-Fi Protected Setup (WPS) implementation on Corega CG-WLR300GNV and CG-WLR300GNV-W devices does not restrict the number of PIN authentication attempts, which makes it easier for remote attackers to obtain network access via a brute-force attack.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 02/09/2019
The vulnerability identified as CVE-2016-4824 affects the Wi-Fi Protected Setup implementation on specific Corega wireless routers including the CG-WLR300GNV and CG-WLR300GNV-W models. This weakness resides in the authentication mechanism that governs the WPS protocol, which is designed to simplify the process of connecting wireless devices to protected networks. The flaw manifests as an inadequate restriction on the number of PIN authentication attempts, creating a significant security risk that directly impacts network access control and overall system integrity. The vulnerability operates at the network infrastructure level, specifically targeting the wireless access point functionality that manages device connections and authentication processes.
The technical implementation flaw stems from the absence of proper rate limiting or account lockout mechanisms within the WPS PIN validation process. This allows attackers to repeatedly attempt PIN guesses without encountering any form of temporary blocking or account restriction. The WPS protocol was originally designed with convenience in mind, enabling users to connect devices by simply entering a PIN rather than managing complex passwords. However, this convenience comes at a cost when proper security controls are not implemented, as demonstrated in this case. The vulnerability specifically affects the authentication flow where the router accepts PIN attempts without enforcing any reasonable limits on the number of attempts, making it susceptible to automated brute-force attacks.
The operational impact of this vulnerability is substantial, as it provides remote attackers with a straightforward path to compromise the wireless network. An attacker can systematically try different PIN combinations using automated tools, potentially gaining unauthorized access to the network within a reasonable timeframe. This vulnerability particularly affects networks that have WPS enabled, which is often enabled by default on many consumer-grade devices to improve user experience. The risk is amplified because the attack can be conducted remotely without requiring physical access to the device or network, making it an attractive target for malicious actors seeking to exploit weak authentication mechanisms. The potential consequences include unauthorized network access, data interception, and the possibility of using the compromised network as a launchpad for further attacks within the network infrastructure.
The vulnerability aligns with CWE-307, which addresses improper restriction of repeated access attempts, and represents a classic example of inadequate access control measures. From an ATT&CK framework perspective, this weakness maps to T1110.003, which covers Brute Force: Password Guessing, demonstrating how the lack of authentication attempt limits enables credential guessing attacks. The vulnerability also relates to T1046, Network Service Scanning, as attackers may use this weakness to identify and exploit devices with weak WPS implementations. Effective mitigations include disabling WPS functionality entirely on affected devices, implementing proper authentication attempt limits, and ensuring that network administrators regularly audit and update device configurations. Organizations should also consider implementing network segmentation and additional monitoring controls to detect and respond to unauthorized access attempts. The recommended approach involves disabling WPS on all wireless infrastructure and replacing vulnerable devices with models that properly implement authentication controls to prevent brute-force attacks.