Source: cve@mitre.org
The WPA2 implementation on the Belkin N900 F9K1104v1 router establishes a WPS PIN based on 6 digits of the LAN/WLAN MAC address, which makes it easier for remote attackers to obtain access to a Wi-Fi network by reading broadcast packets, a different vulnerability than CVE-2012-4366.
Belkin N900 F9K1104v1 routers are vulnerable to remote Wi-Fi network compromise. This vulnerability allows attackers to derive the WPS PIN from the router's MAC address, granting unauthorized access to the Wi-Fi network and potentially sensitive data. This is a critical security flaw that can lead to data breaches and network control.
Step 1: MAC Address Acquisition: The attacker passively monitors Wi-Fi traffic to obtain the router's MAC address. This can be done using readily available network sniffing tools like Wireshark or aircrack-ng. Step 2: PIN Derivation: The attacker extracts the last six digits of the router's MAC address. These six digits are used as the basis for the WPS PIN. Step 3: WPS PIN Brute-Force: The attacker uses the derived digits to calculate the WPS PIN. Since the PIN is based on the MAC address, the attacker can quickly determine the correct PIN. Step 4: WPS Authentication: The attacker uses the calculated PIN to authenticate to the router's Wi-Fi network via the WPS protocol. This grants them access to the network without needing the pre-shared key (PSK).
The vulnerability stems from a flawed implementation of the Wi-Fi Protected Setup (WPS) feature. The router's firmware generates the WPS PIN based on the last six digits of the router's MAC address. This predictable PIN generation allows attackers to easily brute-force the PIN, bypassing the intended security of the WPS protocol. The root cause is a lack of randomness in the PIN generation process, making it susceptible to offline attacks. The MAC address is a publicly broadcasted piece of information, making it trivial to obtain. The firmware does not implement any rate limiting or other security measures to prevent brute-force attempts. This is a design flaw, not a coding error such as a buffer overflow or SQL injection.
While no specific APTs are directly linked to this CVE, the ease of exploitation makes it a target for various threat actors, including those seeking to gain initial access to a network. This vulnerability could be leveraged by attackers for reconnaissance, lateral movement, and data exfiltration. Not listed on CISA KEV due to the age of the vulnerability and the limited impact of the affected devices in modern networks.
Monitor network traffic for WPS authentication attempts, especially those originating from unexpected MAC addresses.
Analyze router logs for failed WPS PIN attempts. A high number of failed attempts could indicate a brute-force attack.
Use network intrusion detection systems (IDS) configured to detect WPS brute-force attacks.
Examine network traffic for WPS packets, looking for unusual patterns or attempts to bypass authentication.
Disable WPS on the Belkin N900 F9K1104v1 router. This is the most effective mitigation strategy.
Upgrade to a router with a patched firmware version. Unfortunately, no patches are available for this specific device.
Change the default Wi-Fi password to a strong, unique password.
Implement network segmentation to limit the impact of a potential breach.
Regularly audit network security configurations.