CVE-2023-44828
📋 TL;DR
This vulnerability in D-Link DIR-823G routers allows attackers to trigger a buffer overflow via the CurrentPassword parameter, potentially causing a Denial of Service (DoS) by crashing the device. It affects users of specific D-Link router models running vulnerable firmware versions. Attackers can exploit this remotely without authentication.
💻 Affected Systems
- D-Link DIR-823G
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device crash requiring physical reset, potential remote code execution if buffer overflow can be controlled precisely (though not confirmed in this CVE).
Likely Case
Denial of Service causing router reboot or crash, disrupting network connectivity for all connected devices.
If Mitigated
Minimal impact if device is behind firewall with restricted access or if vulnerable interface is not exposed.
🎯 Exploit Status
Public proof-of-concept code exists showing buffer overflow trigger. Exploit requires sending crafted HTTP request to web interface.
🛠️ 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. Log into D-Link router web interface. 2. Navigate to firmware update section. 3. Download latest firmware from D-Link support site. 4. Upload and apply firmware update. 5. Router will reboot automatically.
🔧 Temporary Workarounds
Disable remote management
allPrevent external access to router web interface
Change default admin password
allUse strong unique password for router administration
🧯 If You Can't Patch
- Isolate router on separate VLAN with restricted access
- Implement network firewall rules to block access to router web interface from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under Maintenance > Firmware or similar sectionCheck Version:
No CLI command - check via web interface or router labelVerify Fix Applied:
Confirm firmware version matches or exceeds patched version from D-Link advisory📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts with malformed password fields
- Router reboot/crash logs
- Unusual HTTP requests to login or password change endpoints
Network Indicators:
- HTTP POST requests with unusually long CurrentPassword parameter
- Traffic to router web interface from external IPs
SIEM Query:
source="router_logs" AND (event="crash" OR event="reboot" OR (uri="/login.cgi" AND param_length>100))