CVE-2024-33623 Overview
CVE-2024-33623 is a denial of service vulnerability in the Web Application functionality of the LevelOne WBR-6012 wireless router running firmware R0.40e6. A specially crafted HTTP request sent to the device causes the router to reboot, interrupting all network connectivity for connected clients. The flaw is categorized under [CWE-835] (Loop with Unreachable Exit Condition) and requires no authentication or user interaction to trigger.
The vulnerability is reachable over the network from any attacker with HTTP access to the device management interface. Talos Intelligence documented the issue in advisory TALOS-2024-2001.
Critical Impact
An unauthenticated remote attacker can force the WBR-6012 router to reboot by sending a single crafted HTTP request, resulting in repeated denial of service for all downstream users.
Affected Products
- LevelOne WBR-6012 router (hardware revision R0)
- LevelOne WBR-6012 firmware version R0.40e6
- Networks exposing the device web management interface to untrusted clients
Discovery Timeline
- 2024-10-30 - CVE-2024-33623 published to NVD
- 2024-11-21 - Last updated in NVD database
Technical Details for CVE-2024-33623
Vulnerability Analysis
The LevelOne WBR-6012 web administration interface processes incoming HTTP requests through firmware that fails to safely handle a specific malformed input pattern. Processing the crafted request leads the device into an unrecoverable state that terminates with a system reboot. The classification under [CWE-835] indicates the request drives the firmware into a loop or condition with no proper exit, exhausting resources until the watchdog forces a restart.
The attack requires only network reachability to the HTTP service on the router. No credentials, configuration changes, or user interaction are needed. Repeated requests can keep the device in a continuous reboot cycle, denying service to all connected clients indefinitely.
Root Cause
The root cause is improper input validation and loop control in the HTTP request handler of the WBR-6012 web application firmware. The handler does not enforce safe bounds or proper termination conditions when parsing the crafted request, allowing the request to drive the device into an unstable state that the firmware resolves by rebooting.
Attack Vector
An attacker reaches the vulnerability by sending a single crafted HTTP request to the device web interface. Where the management interface is exposed to the WAN, the attack is possible from the public internet. On a LAN, any malicious client, compromised host, or unauthorized wireless guest can trigger the reboot. Talos Intelligence published technical reproduction details in TALOS-2024-2001.
No public proof-of-concept exploit code is referenced in the NVD entry, and no working exploit is listed in ExploitDB at the time of publication.
Detection Methods for CVE-2024-33623
Indicators of Compromise
- Unexpected reboots of the WBR-6012 router with no administrator-initiated trigger
- Bursts of HTTP traffic to the router management interface from a single source immediately before reboot events
- Repeated short-interval outages in DHCP lease logs or upstream ISP connection logs
Detection Strategies
- Monitor router uptime through SNMP or syslog and alert on reboot frequencies above baseline
- Inspect network flow records for unusual HTTP request volume or malformed requests directed at the router management IP
- Correlate device reboot events with HTTP access log entries from the router where logging is supported
Monitoring Recommendations
- Forward router syslog data to a central log platform and create alerts on reboot or watchdog reset messages
- Track HTTP source addresses contacting the device admin interface and flag any external sources
- Review wireless association logs for clients present at the time of repeated reboots
How to Mitigate CVE-2024-33623
Immediate Actions Required
- Restrict access to the WBR-6012 web administration interface to trusted management hosts only
- Disable WAN-side access to the HTTP management service if currently enabled
- Segment guest and untrusted wireless clients away from the management VLAN or subnet
- Replace the device with a supported router if the vendor does not publish a firmware fix
Patch Information
No vendor patch is referenced in the NVD entry or vendor advisory listings for CVE-2024-33623 at the time of publication. Administrators should consult the Talos Intelligence advisory TALOS-2024-2001 and the LevelOne support site for any subsequent firmware release addressing the issue.
Workarounds
- Place the router behind an upstream firewall and block inbound TCP traffic to the HTTP management port from untrusted sources
- Apply firewall rules on the device itself to permit management access only from a defined administrative subnet
- Use a wired-only management workflow and disable wireless access to the admin interface where feasible
# Example upstream firewall rule restricting access to the router admin interface
# Replace 192.0.2.10 with the router IP and 198.51.100.0/24 with the admin subnet
iptables -A FORWARD -p tcp -d 192.0.2.10 --dport 80 -s 198.51.100.0/24 -j ACCEPT
iptables -A FORWARD -p tcp -d 192.0.2.10 --dport 80 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
