CVE-2025-50757
📋 TL;DR
This CVE describes a command injection vulnerability in Wavlink WN535K3 routers that allows attackers to execute arbitrary system commands by manipulating the username parameter in the set_sys_adm function. Attackers can potentially gain full control of affected devices. This affects users of Wavlink WN535K3 routers running the vulnerable firmware version.
💻 Affected Systems
- Wavlink WN535K3
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing attackers to install persistent backdoors, pivot to internal networks, intercept traffic, or use the device as part of a botnet.
Likely Case
Attackers gain shell access to the router, enabling them to modify configurations, intercept network traffic, or use the device for further attacks.
If Mitigated
Limited impact if device is behind firewall with restricted administrative access and network segmentation.
🎯 Exploit Status
Exploitation requires access to the administrative interface. The vulnerability is in a specific function that handles username parameter validation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Wavlink for updated firmware
Vendor Advisory: Not publicly available at time of analysis
Restart Required: Yes
Instructions:
1. Check Wavlink support site for firmware updates. 2. Download latest firmware for WN535K3. 3. Log into router admin interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router after update completes.
🔧 Temporary Workarounds
Restrict Administrative Access
allLimit access to router administrative interface to trusted IP addresses only
Disable Remote Administration
allTurn off remote administration features if not required
🧯 If You Can't Patch
- Isolate the router on a dedicated network segment with strict firewall rules
- Implement network monitoring for suspicious administrative access attempts
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is 20191010, device is vulnerable.Check Version:
Log into router web interface and check System Status or Firmware Information pageVerify Fix Applied:
After updating firmware, verify version has changed from 20191010 and test administrative functions work normally.📡 Detection & Monitoring
Log Indicators:
- Unusual administrative login attempts
- Suspicious commands in system logs
- Multiple failed login attempts followed by successful login
Network Indicators:
- Unusual outbound connections from router
- Traffic to known malicious IPs from router
- Port scanning originating from router
SIEM Query:
source="router_logs" AND ("set_sys_adm" OR "username=" AND command_execution_patterns)