CVE-2019-17506
📋 TL;DR
This vulnerability allows unauthenticated attackers to retrieve router credentials and other sensitive information from D-Link routers via a web interface authentication bypass. Attackers can exploit this to gain administrative access and control affected routers remotely. Users of specific D-Link router models with vulnerable firmware versions are affected.
💻 Affected Systems
- D-Link DIR-868L
- D-Link DIR-817LW
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete router compromise allowing attackers to intercept all network traffic, redirect DNS, install malware, and use the router as an attack platform.
Likely Case
Router takeover enabling network surveillance, credential theft from connected devices, and potential lateral movement into internal networks.
If Mitigated
Limited impact if routers are behind firewalls with restricted WAN access and strong network segmentation.
🎯 Exploit Status
Simple HTTP request with crafted parameters. Public exploit scripts available on GitHub.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link support for latest firmware
Vendor Advisory: https://support.dlink.com/
Restart Required: Yes
Instructions:
1. Visit D-Link support site. 2. Download latest firmware for your model. 3. Log into router admin panel. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Change Default Credentials
allUse strong, unique admin password
🧯 If You Can't Patch
- Place router behind firewall with strict inbound rules
- Implement network segmentation to isolate router management interface
🔍 How to Verify
Check if Vulnerable:
Test if http://[router-ip]/getcfg.php?SERVICES=DEVICE.ACCOUNT&AUTHORIZED_GROUP=1%0a returns credentials without authenticationCheck Version:
Check router web interface admin panel for firmware versionVerify Fix Applied:
Attempt exploit after patching - should return error or no credentials📡 Detection & Monitoring
Log Indicators:
- HTTP requests to getcfg.php with AUTHORIZED_GROUP parameter
- Multiple failed login attempts followed by successful access
Network Indicators:
- Unusual outbound connections from router
- DNS changes or redirects
SIEM Query:
source="router_logs" AND uri="*getcfg.php*" AND query="*AUTHORIZED_GROUP*"