CVE-2024-50997
📋 TL;DR
This vulnerability allows attackers to cause a Denial of Service (DoS) on affected Netgear routers by sending a specially crafted POST request to the pptp.cgi endpoint. The stack overflow in the pptp_user_ip parameter can crash the router service or device. Users of Netgear R8500, XR300, R7000P, and R6400 v2 routers with specific vulnerable firmware versions are affected.
💻 Affected Systems
- Netgear R8500
- Netgear XR300
- Netgear R7000P
- Netgear R6400 v2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router crash requiring physical reboot, potentially disrupting all network connectivity for connected devices.
Likely Case
Temporary service disruption affecting PPTP functionality and potentially other router services until automatic or manual restart.
If Mitigated
Minimal impact if routers are behind firewalls with restricted WAN access or if PPTP functionality is disabled.
🎯 Exploit Status
Exploitation requires access to the router's web interface, though authentication status is unclear from available information.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://www.netgear.com/about/security/
Restart Required: Yes
Instructions:
1. Check Netgear security advisory for firmware updates. 2. Download appropriate firmware from Netgear support site. 3. Access router web interface. 4. Navigate to Administration > Firmware Upgrade. 5. Upload and install new firmware. 6. Wait for router to reboot.
🔧 Temporary Workarounds
Disable PPTP Service
allTurn off PPTP functionality to remove the vulnerable endpoint.
Restrict Web Interface Access
allLimit access to router administration interface to trusted IP addresses only.
🧯 If You Can't Patch
- Place routers behind firewalls with strict inbound rules blocking access to web administration ports
- Disable remote administration and ensure web interface is only accessible from internal network
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under Advanced > Administration > Router Status or similar menu.Check Version:
No CLI command available; check via web interface or Netgear mobile app.Verify Fix Applied:
Verify firmware version has been updated to a version newer than those listed in affected systems.📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to pptp.cgi endpoint
- Router service crashes or restarts
- Unusual traffic to router administration port
Network Indicators:
- HTTP POST requests to /pptp.cgi with malformed pptp_user_ip parameter
- Traffic to router web interface from unexpected sources
SIEM Query:
http.method:POST AND http.uri:"*pptp.cgi*" AND (http.user_agent NOT IN ["expected_user_agents"] OR src_ip NOT IN ["trusted_networks"])