CVE-2025-55603
📋 TL;DR
A buffer overflow vulnerability exists in Tenda AX3 routers running firmware version V16.03.12.10_CN. Attackers can exploit this by sending specially crafted NTP server parameters to the fromSetSysTime function, potentially allowing remote code execution. This affects users who have not updated their router firmware.
💻 Affected Systems
- Tenda AX3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote attacker gains full control of the router, enabling traffic interception, credential theft, and lateral movement into the internal network.
Likely Case
Router crashes or becomes unstable, causing denial of service and network disruption.
If Mitigated
Attack fails due to input validation or memory protections, resulting in no impact.
🎯 Exploit Status
Exploit details are publicly available in GitHub repositories, making weaponization probable.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
Check Tenda's official website or support portal for firmware updates. If an update is available, download and install it via the router's web interface, then restart the device.
🔧 Temporary Workarounds
Disable Remote Management
allPrevents external access to the vulnerable function by disabling remote administration features.
Access router web interface > Advanced Settings > Remote Management > Disable
Restrict NTP Server Input
allLimit NTP server configuration to trusted, internal servers only.
Access router web interface > System Tools > Time Settings > Set NTP server to a trusted IP
🧯 If You Can't Patch
- Segment the network to isolate the router from critical systems.
- Implement strict firewall rules to block unnecessary inbound traffic to the router.
🔍 How to Verify
Check if Vulnerable:
Check the router's firmware version via the web interface: Login > System Status > Firmware Version.Check Version:
Not applicable; use web interface as above.Verify Fix Applied:
After updating, verify the firmware version is no longer V16.03.12.10_CN.📡 Detection & Monitoring
Log Indicators:
- Unusual NTP configuration requests
- Router crash logs or reboots
Network Indicators:
- Malformed packets to router's management interface on port 80/443
SIEM Query:
source_ip="router_ip" AND (http_uri CONTAINS "setSysTime" OR http_post_data CONTAINS "ntpServer")