Source: cret@cert.org
The web management interface on Belkin F9K1102 2 devices with firmware 2.10.17 has a blank password, which allows remote attackers to obtain administrative privileges by leveraging a LAN session.
Belkin F9K1102 routers running firmware 2.10.17 are vulnerable to a critical security flaw. This vulnerability allows unauthenticated remote attackers on the local network to gain administrative access due to a blank default password on the web management interface, potentially leading to complete network compromise and data exfiltration.
Step 1: Network Access: The attacker must be on the same local network (LAN) as the vulnerable Belkin router.
Step 2: Web Interface Access: The attacker opens a web browser and navigates to the router's web management interface URL (typically an IP address like 192.168.2.1).
Step 3: Authentication Bypass: The attacker leaves the username and password fields blank on the login page and submits the form.
Step 4: Administrative Access Granted: The router's web interface, due to the blank password configuration, grants the attacker administrative access without requiring any credentials.
Step 5: System Compromise: The attacker, now with administrative privileges, can modify router settings, install malicious firmware, or intercept network traffic, effectively compromising the network.
The vulnerability stems from a fundamental design flaw: the web management interface of the Belkin F9K1102 router with firmware 2.10.17 does not enforce any authentication for administrative access. Specifically, the default configuration sets the administrator password to blank. This means that any user on the local area network (LAN) can access the router's web interface and gain administrative privileges simply by navigating to the management URL and leaving the password field empty. This lack of authentication allows attackers to modify network settings, install malicious firmware, intercept network traffic, and potentially pivot to other systems on the network. The root cause is a failure to implement secure default configurations and a lack of proper authentication mechanisms.
While specific APT groups are not directly linked to this specific CVE, the ease of exploitation makes it attractive to various threat actors. The vulnerability could be leveraged by opportunistic attackers for initial access. This vulnerability is not listed on the CISA KEV catalog, but its impact warrants consideration for inclusion.
Monitor network traffic for unauthorized access to the router's web management interface (e.g., HTTP/HTTPS requests to the router's IP address).
Analyze router logs for suspicious activity, such as configuration changes or firmware updates performed by unknown users or IP addresses.
Implement network intrusion detection systems (IDS) with rules to detect attempts to access the router's web interface without proper authentication.
Regularly scan the network for vulnerable devices using vulnerability scanners.
Monitor for unusual network traffic patterns originating from the router, such as unexpected outbound connections or data transfers.
Upgrade the router's firmware to a patched version (if available).
If a firmware update is unavailable, replace the vulnerable router with a secure alternative.
Change the default administrator password to a strong, unique password.
Disable remote administration if not required.
Implement network segmentation to isolate the router from critical network resources.
Regularly audit network configurations and security settings.
Educate users about the risks of connecting to untrusted networks.