CVE-2024-27656
📋 TL;DR
This vulnerability in D-Link DIR-823G routers allows attackers to exploit a buffer overflow via the Cookie parameter. Attackers can cause Denial of Service (DoS) and potentially achieve remote code execution. Users of affected D-Link DIR-823G routers with vulnerable firmware are at risk.
💻 Affected Systems
- D-Link DIR-823G
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, network infiltration, and persistent backdoor installation.
Likely Case
Denial of Service causing router crashes and network disruption, with potential for limited remote code execution.
If Mitigated
DoS attacks causing temporary service disruption until device restart, with code execution prevented by security controls.
🎯 Exploit Status
Buffer overflow via Cookie parameter suggests straightforward exploitation. Public technical details available in references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check D-Link website for firmware updates. 2. Download latest firmware for DIR-823G. 3. Access router web interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Wait for router to restart.
🔧 Temporary Workarounds
Disable Remote Management
allPrevent external access to router web interface
Network Segmentation
allIsolate router management interface to trusted network
🧯 If You Can't Patch
- Replace affected router with updated model or different vendor
- Implement strict firewall rules to block external access to router management interface
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in web interface under System > FirmwareCheck Version:
Not applicable - check via web interfaceVerify Fix Applied:
Verify firmware version is updated beyond A1V1.0.2B05📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests with malformed Cookie headers
- Router crash/restart logs
- Multiple failed login attempts
Network Indicators:
- HTTP requests with unusually long Cookie values to router IP
- Traffic patterns suggesting DoS attacks on router
SIEM Query:
source="router_logs" AND (http_cookie_length>1000 OR message="crash" OR message="reboot")