CVE-2017-18842
📋 TL;DR
This CVE describes a Cross-Site Request Forgery (CSRF) vulnerability in certain NETGEAR routers and gateways. Attackers can trick authenticated users into performing unauthorized actions on their devices. Affected users include those with specific NETGEAR models running outdated firmware.
💻 Affected Systems
- NETGEAR R7300
- NETGEAR R8500
- NETGEAR DGN2200v1
- NETGEAR D2200D
- NETGEAR D2200DW-1FRNAS
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover: attacker changes admin credentials, enables remote access, or reconfigures network settings to intercept traffic.
Likely Case
Unauthorized configuration changes: attacker modifies DNS settings, firewall rules, or network parameters to enable further attacks.
If Mitigated
No impact if proper CSRF protections are in place or if devices are not internet-facing with default credentials changed.
🎯 Exploit Status
CSRF attacks are well-understood and relatively easy to implement. Requires user to be authenticated to the router's web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: R7300: 1.0.0.54+, R8500: 1.0.2.94+, DGN2200v1: 1.0.0.55+, D2200D/D2200DW-1FRNAS: 1.0.0.32+
Vendor Advisory: https://kb.netgear.com/000049017/Security-Advisory-for-a-Cross-Site-Request-Forgery-on-Some-Routers-DSL-Gateways-and-a-Modem-Router-PSV-2017-0327
Restart Required: Yes
Instructions:
1. Log into router web interface. 2. Navigate to firmware update section. 3. Download latest firmware from NETGEAR support site. 4. Upload and install firmware. 5. Reboot device.
🔧 Temporary Workarounds
Log out after administration
allAlways log out of router web interface after making changes to prevent CSRF attacks.
Use separate browser for administration
allUse a dedicated browser or private browsing session only for router administration.
🧯 If You Can't Patch
- Change default admin credentials to strong, unique passwords
- Disable remote administration if not needed
🔍 How to Verify
Check if Vulnerable:
Check firmware version in router web interface under Advanced > Administration > Firmware UpdateCheck Version:
No CLI command - check via web interface at http://routerlogin.net or router IPVerify Fix Applied:
Verify firmware version matches or exceeds patched versions listed in advisory📡 Detection & Monitoring
Log Indicators:
- Multiple configuration changes from same IP in short time
- Unauthorized configuration changes in router logs
Network Indicators:
- Unexpected DNS server changes
- New port forwarding rules
- Changed admin credentials
SIEM Query:
Look for router configuration change events followed by web requests to external domains