CVE-2024-39768
📋 TL;DR
This CVE describes multiple buffer overflow vulnerabilities in the Wavlink AC3000 router's internet.cgi set_qos() function. An authenticated attacker can send specially crafted HTTP requests to trigger stack-based buffer overflows via the cli_name POST parameter, potentially leading to remote code execution. This affects users of Wavlink AC3000 routers with vulnerable firmware versions.
💻 Affected Systems
- Wavlink AC3000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with administrative privileges, allowing complete device takeover, network compromise, and lateral movement to connected systems.
Likely Case
Device crash/reboot causing service disruption, or limited code execution within the router's constrained environment.
If Mitigated
Denial of service through device crash if exploit attempts are blocked or fail.
🎯 Exploit Status
Exploit requires authentication but uses simple buffer overflow techniques. Public details available in Talos report.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Wavlink website for firmware updates. 2. Download latest firmware. 3. Log into router admin interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable QoS functionality
allTurn off Quality of Service feature to prevent access to vulnerable set_qos() function
Change default credentials
allUse strong, unique passwords for router admin interface
🧯 If You Can't Patch
- Isolate router on separate VLAN with strict firewall rules
- Disable remote administration and limit web interface access to trusted IPs only
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router admin interface under System Status or Firmware Update sectionCheck Version:
Login to router web interface and navigate to firmware/status pageVerify Fix Applied:
Verify firmware version matches or exceeds patched version from vendor📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to internet.cgi with long cli_name parameter
- Router crash/reboot logs
- Multiple failed authentication attempts followed by successful login
Network Indicators:
- HTTP traffic to router on port 80/443 with unusually long POST parameters
- Traffic patterns matching exploit payloads
SIEM Query:
source="router_logs" AND (url="*internet.cgi*" AND method="POST" AND param_length>100) OR event="device_reboot"