CVE-2024-52013
📋 TL;DR
This vulnerability is a stack overflow in Netgear routers' pptp_user_ip parameter at wiz_pptp.cgi. Attackers can exploit it via crafted POST requests to cause Denial of Service (DoS), potentially crashing the router. Affected users include those running specific vulnerable Netgear router models and firmware versions.
💻 Affected Systems
- Netgear R8500
- Netgear XR300
- Netgear R7000P
- Netgear R6400 v2
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Router becomes completely unresponsive, requiring physical reboot or factory reset, disrupting all network connectivity.
Likely Case
Router crashes or becomes unstable, causing temporary network outage until reboot.
If Mitigated
Minimal impact if router is behind firewall with restricted WAN access and PPTP disabled.
🎯 Exploit Status
Exploit requires sending crafted POST request to vulnerable endpoint. Public PoC available in GitHub repository.
🛠️ 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 patch availability. 2. If patch exists, download from Netgear support site. 3. Upload firmware via router web interface. 4. Reboot router after update.
🔧 Temporary Workarounds
Disable PPTP Service
allDisable PPTP VPN functionality to remove vulnerable endpoint
Login to router admin interface
Navigate to Advanced > VPN Service
Disable PPTP VPN
Restrict Web Management Access
allLimit web interface access to trusted internal IPs only
Login to router admin interface
Navigate to Advanced > Administration
Set 'Allow only specified IPs' for web management
🧯 If You Can't Patch
- Place router behind firewall with strict inbound rules blocking access to web management port (typically 80/443)
- Disable remote management and ensure web interface is only accessible from internal network
🔍 How to Verify
Check if Vulnerable:
Check router firmware version matches affected versions. Test by attempting to access wiz_pptp.cgi endpoint.Check Version:
Login to router web interface and check firmware version in Advanced > Administration > Router UpdateVerify Fix Applied:
Verify firmware version is updated beyond vulnerable versions. Test that wiz_pptp.cgi endpoint no longer accepts malformed POST requests.📡 Detection & Monitoring
Log Indicators:
- Multiple POST requests to wiz_pptp.cgi with large pptp_user_ip parameter
- Router crash/reboot logs
- Unusual traffic to router web management port
Network Indicators:
- HTTP POST requests to /wiz_pptp.cgi with oversized parameters
- Sudden loss of router connectivity
SIEM Query:
source="router_logs" AND (uri="/wiz_pptp.cgi" AND method="POST" AND size>1000)