CVE-2025-4867 Overview
CVE-2025-4867 affects the Tenda A15 wireless router running firmware version 15.13.07.13. The vulnerability resides in the formArpNerworkSet function handling requests to the /goform/ArpNerworkSet endpoint. Attackers can trigger a denial of service condition by manipulating input to this function remotely over the network. The flaw is categorized under [CWE-404] (Improper Resource Shutdown or Release). Public disclosure of the exploit details has occurred, increasing the likelihood of opportunistic exploitation against exposed devices.
Critical Impact
Remote attackers with low-level authentication can crash the router's web management service, disrupting network connectivity for all downstream users.
Affected Products
- Tenda A15 Router (hardware)
- Tenda A15 Firmware version 15.13.07.13
- Deployments exposing the /goform/ArpNerworkSet web management endpoint
Discovery Timeline
- 2025-05-18 - CVE-2025-4867 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-4867
Vulnerability Analysis
The vulnerability is a remotely exploitable denial of service in the Tenda A15 router firmware. The flaw sits in the formArpNerworkSet handler, which processes HTTP requests sent to /goform/ArpNerworkSet. Improper resource handling in this function causes the service to terminate or hang when it receives crafted input. The attack requires network reachability to the device's management interface and low-privilege authentication. Successful exploitation disrupts router operations and interrupts connectivity for connected clients until the device recovers or is restarted.
Root Cause
The root cause maps to [CWE-404] Improper Resource Shutdown or Release. The formArpNerworkSet function fails to properly validate or release resources tied to ARP network configuration parameters. When processing malformed or unexpected input, the handler enters a state where resources are not cleaned up, resulting in service failure. This class of defect is common in embedded web management interfaces that reuse C-based CGI handlers without rigorous input validation.
Attack Vector
Exploitation occurs over the network against the router's HTTP management interface. An attacker sends a crafted POST request to /goform/ArpNerworkSet with manipulated parameters that trigger the resource handling defect. The exploit has been publicly disclosed through the GitHub notification published by the reporter and tracked in VulDB entry #309409. Devices with management interfaces exposed to untrusted networks are at the highest risk.
No verified proof-of-concept code is provided here. Refer to the external advisory for technical reproduction steps.
Detection Methods for CVE-2025-4867
Indicators of Compromise
- HTTP POST requests targeting /goform/ArpNerworkSet from unexpected source addresses
- Repeated router reboots or management interface timeouts coinciding with inbound HTTP traffic
- Loss of ARP table consistency or sudden drops in client connectivity through the affected device
Detection Strategies
- Inspect HTTP access logs on the router or upstream security appliances for requests to /goform/ArpNerworkSet containing malformed parameters
- Correlate authentication events for the router administration interface with subsequent service unavailability
- Deploy network intrusion detection signatures targeting known exploit patterns referenced in VulDB CTI #309409
Monitoring Recommendations
- Monitor availability of the router management plane and alert on repeated service restarts
- Track inbound WAN-side connections to the device's HTTP or HTTPS management ports and block untrusted sources
- Log administrative session activity to identify low-privilege accounts issuing abnormal configuration requests
How to Mitigate CVE-2025-4867
Immediate Actions Required
- Restrict access to the router's web management interface to trusted LAN segments only, blocking WAN exposure
- Change default administrative credentials and enforce strong passwords to reduce the risk of low-privilege abuse
- Audit all deployed Tenda A15 units for firmware version 15.13.07.13 and schedule replacement or isolation
Patch Information
At the time of publication, no vendor patch has been referenced in the available advisories. Monitor the Tenda official website for firmware updates addressing CVE-2025-4867. In the absence of a vendor fix, mitigation relies on network segmentation and access control.
Workarounds
- Disable remote (WAN) administration on the router and enforce administration only from trusted internal hosts
- Place affected devices behind a network firewall that filters inbound requests to the management interface
- Consider replacing end-of-support consumer-grade routers with devices from vendors providing active security maintenance
# Example: restrict router admin interface to a management subnet using iptables on an upstream gateway
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -s 192.168.10.0/24 -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 80 -j DROP
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -s 192.168.10.0/24 -j ACCEPT
iptables -A FORWARD -p tcp -d <router_ip> --dport 443 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
