CVE-2025-63455 Overview
A stack overflow vulnerability has been identified in the Tenda AX-3 router firmware version 16.03.12.10_CN. The vulnerability exists in the fromSetWifiGusetBasic function, which improperly handles the shareSpeed parameter. This flaw allows remote attackers to trigger a Denial of Service (DoS) condition by sending specially crafted requests to the affected device.
Critical Impact
Remote attackers can exploit this vulnerability to crash affected Tenda AX-3 routers without authentication, causing network service disruption for all connected devices.
Affected Products
- Tenda AX3 Firmware version 16.03.12.10_CN
- Tenda AX3 Hardware
Discovery Timeline
- 2025-11-10 - CVE-2025-63455 published to NVD
- 2025-11-17 - Last updated in NVD database
Technical Details for CVE-2025-63455
Vulnerability Analysis
This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow). The flaw resides in the fromSetWifiGusetBasic function within the Tenda AX-3 router firmware. When processing user-supplied input through the shareSpeed parameter, the function fails to properly validate the length of the incoming data before copying it to a fixed-size stack buffer.
The vulnerability can be triggered remotely over the network without requiring any authentication or user interaction. Successful exploitation results in corruption of stack memory, leading to a crash of the affected service or the entire device, effectively denying network connectivity to all users relying on the router.
Root Cause
The root cause of this vulnerability is improper bounds checking in the fromSetWifiGusetBasic function. When the shareSpeed parameter receives input data exceeding the expected buffer size, the function writes beyond the allocated stack buffer boundaries. This stack-based buffer overflow occurs because the firmware does not implement adequate input length validation before memory copy operations.
Attack Vector
The attack can be executed remotely over the network. An attacker needs to craft a malicious HTTP request containing an oversized value in the shareSpeed parameter and send it to the router's web management interface. The fromSetWifiGusetBasic function processes this parameter as part of the WiFi guest network configuration functionality.
The exploitation does not require authentication, meaning any attacker with network access to the router's management interface can trigger the vulnerability. The attack complexity is low, as the attacker simply needs to send a crafted request with an excessively long shareSpeed parameter value to cause the stack overflow and subsequent denial of service.
Technical details and proof-of-concept information are available in the GitHub Vulnerability Report.
Detection Methods for CVE-2025-63455
Indicators of Compromise
- Unexpected router reboots or crashes, particularly after receiving HTTP requests to the management interface
- Network connectivity interruptions affecting all connected devices
- Abnormal traffic patterns targeting the router's web management interface with large parameter values
- System logs showing crashes or memory errors in the web server process
Detection Strategies
- Monitor network traffic for HTTP requests to the router's management interface containing unusually large shareSpeed parameter values
- Implement network intrusion detection rules to identify potential buffer overflow attempts targeting the fromSetWifiGusetBasic endpoint
- Deploy network monitoring to detect repeated connection attempts to the router's administrative interface from external sources
- Configure alerting for unexpected device reboots or service interruptions on Tenda AX-3 routers
Monitoring Recommendations
- Enable logging on network firewalls to capture traffic destined for router management interfaces
- Implement continuous availability monitoring for critical network infrastructure including routers
- Review access logs for the router's web interface for suspicious request patterns
- Consider network segmentation to isolate management interfaces from untrusted networks
How to Mitigate CVE-2025-63455
Immediate Actions Required
- Restrict access to the router's web management interface to trusted IP addresses only
- Disable remote management access from the WAN interface if not required
- Place the router behind a firewall that can filter malicious requests
- Monitor for firmware updates from Tenda that address this vulnerability
Patch Information
As of the last NVD update on 2025-11-17, no official patch has been released by Tenda for this vulnerability. Users should monitor Tenda's official support channels and firmware download pages for security updates addressing this stack overflow issue. Consider replacing affected devices with alternative hardware if no patch becomes available in a reasonable timeframe.
Workarounds
- Disable the web-based management interface if not actively required for administration
- Configure firewall rules to block external access to the router's management ports
- Use network ACLs to restrict management interface access to specific trusted hosts
- Consider implementing a VPN for remote management instead of exposing the web interface directly
# Example firewall rule to restrict management access (adjust for your environment)
# Block external access to router management interface
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! 192.168.1.0/24 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
