CVE-2026-3612
📋 TL;DR
This CVE describes a command injection vulnerability in Wavlink WL-NU516U1 routers that allows remote attackers to execute arbitrary commands on affected devices. The vulnerability exists in the OTA Online Upgrade component's firmware URL parameter, enabling attackers to take control of vulnerable routers. Anyone using Wavlink WL-NU516U1 routers with firmware version V240425 is affected.
💻 Affected Systems
- Wavlink WL-NU516U1
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete device compromise allowing persistent backdoor installation, network pivoting to internal systems, data exfiltration, and botnet recruitment.
Likely Case
Router takeover enabling traffic interception, DNS hijacking, credential theft, and lateral movement within the network.
If Mitigated
Limited impact if device is isolated with strict network segmentation and outbound filtering.
🎯 Exploit Status
Public exploit details available on GitHub. The vulnerability requires no authentication and has simple exploitation vectors.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Contact Wavlink support for patch availability. 2. If patch exists, download from official vendor site. 3. Upload firmware via admin interface. 4. Reboot device after installation.
🔧 Temporary Workarounds
Disable OTA Online Upgrade
allTurn off automatic firmware updates in router settings to prevent exploitation via firmware_url parameter.
Network Segmentation
allIsolate vulnerable routers in separate VLAN with restricted access to critical internal resources.
🧯 If You Can't Patch
- Immediately disconnect vulnerable devices from internet-facing interfaces
- Implement strict egress filtering to prevent command-and-control communication
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface. If version is V240425, device is vulnerable.Check Version:
Check via router web interface at http://[router-ip]/ or using SSH if available: cat /etc/versionVerify Fix Applied:
Verify firmware version has changed from V240425 to a newer patched version.📡 Detection & Monitoring
Log Indicators:
- Unusual firmware upgrade attempts
- Suspicious commands in system logs
- Unexpected process execution
Network Indicators:
- Outbound connections to unusual IPs/ports after exploitation
- DNS queries to suspicious domains
- Unusual traffic patterns from router
SIEM Query:
source="router_logs" AND ("firmware_url" OR "adm.cgi" OR "sub_405AF4") AND command="*"