CVE-2023-44838
📋 TL;DR
This vulnerability in D-Link DIR-823G routers allows attackers to trigger a buffer overflow by sending specially crafted input to the TXPower parameter. This can cause a Denial of Service (DoS) by crashing the device. Only users of the specific D-Link DIR-823G A1 hardware with vulnerable firmware are affected.
💻 Affected Systems
- D-Link DIR-823G A1
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical power cycle, potentially disrupting all network connectivity for connected devices.
Likely Case
Router becomes unresponsive, requiring reboot to restore functionality, causing temporary network outage.
If Mitigated
No impact if device is patched or network access is properly restricted.
🎯 Exploit Status
Public proof-of-concept code exists, making exploitation straightforward for attackers with network access to the device.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check D-Link security bulletin for latest patched version
Vendor Advisory: https://www.dlink.com/en/security-bulletin/
Restart Required: Yes
Instructions:
1. Visit D-Link support site 2. Download latest firmware for DIR-823G A1 3. Log into router admin interface 4. Navigate to firmware update section 5. Upload and apply new firmware 6. Reboot router
🔧 Temporary Workarounds
Network Access Restriction
allRestrict access to router admin interface to trusted internal IPs only
Disable Remote Management
allTurn off remote administration features if not required
🧯 If You Can't Patch
- Segment router on isolated network segment with strict firewall rules
- Implement network monitoring for abnormal traffic to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router web interface or serial console for firmware version V1.0.2B05Check Version:
Check router admin interface under System or Firmware sectionVerify Fix Applied:
Verify firmware version has been updated to a version newer than V1.0.2B05📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts to admin interface
- Router crash/reboot logs
- Unusual POST requests to wireless configuration endpoints
Network Indicators:
- Abnormal traffic to router port 80/443 from external sources
- Repeated connection attempts to /goform/setWLanRadioSettings
SIEM Query:
source_ip=external AND dest_ip=router_ip AND (uri_path="/goform/setWLanRadioSettings" OR user_agent_contains="exploit")