CVE-2025-36747
📋 TL;DR
CVE-2025-36747 is a critical vulnerability in ShineLan-X firmware where hardcoded FTP credentials allow attackers to establish insecure connections. This enables file replacement attacks since firmware signature verification is not enforced, potentially compromising all devices running vulnerable firmware. Organizations using ShineLan-X networking equipment are affected.
💻 Affected Systems
- ShineLan-X networking equipment
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete device takeover allowing persistent backdoor installation, network traffic interception, lateral movement to other systems, and disruption of critical network infrastructure.
Likely Case
Malicious firmware deployment leading to data exfiltration, network monitoring, or ransomware deployment on affected devices.
If Mitigated
Limited impact with proper network segmentation and monitoring, though credential exposure remains a security concern.
🎯 Exploit Status
Exploitation requires network access to FTP service but uses publicly known hardcoded credentials. No authentication bypass needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: https://csirt.divd.nl/CVE-2025-36747/
Restart Required: Yes
Instructions:
1. Monitor vendor for firmware updates. 2. Apply firmware patch when available. 3. Restart affected devices after patching.
🔧 Temporary Workarounds
Block FTP Access
linuxBlock inbound FTP connections to affected devices using network firewalls
iptables -A INPUT -p tcp --dport 21 -j DROP
Network Segmentation
allIsolate ShineLan-X devices in separate VLAN with strict access controls
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected devices from critical systems
- Deploy network monitoring and IDS/IPS to detect FTP connection attempts and file transfer anomalies
🔍 How to Verify
Check if Vulnerable:
Check if FTP service is accessible on port 21 and test connection using known hardcoded credentials from firmware analysisCheck Version:
Check device web interface or CLI for firmware version informationVerify Fix Applied:
Verify FTP service is no longer accessible or requires proper authentication, and firmware signature verification is enforced📡 Detection & Monitoring
Log Indicators:
- FTP authentication attempts from unexpected sources
- FTP file uploads to firmware directories
- FTP connection logs showing successful authentication
Network Indicators:
- FTP traffic to ShineLan-X devices on port 21
- Unusual file transfers to firmware update locations
SIEM Query:
source_port=21 AND (dest_ip=SHINELAN_DEVICES) AND (event_type="ftp_auth_success" OR event_type="ftp_file_upload")