CVE-2023-25094
📋 TL;DR
This vulnerability allows authenticated attackers with high privileges to execute arbitrary code on Milesight UR32L routers by sending specially crafted HTTP requests. The buffer overflow occurs in the vtysh_ubus binary due to unsafe sprintf usage, potentially giving attackers full system control. Only Milesight UR32L routers running vulnerable firmware versions are affected.
💻 Affected Systems
- Milesight UR32L
📦 What is this software?
Ur32l Firmware by Milesight
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install persistent backdoors, pivot to internal networks, or disrupt critical infrastructure operations.
Likely Case
Privilege escalation leading to unauthorized configuration changes, data exfiltration, or use as a foothold for lateral movement.
If Mitigated
Limited impact if proper network segmentation and privilege controls prevent high-privilege access to vulnerable interfaces.
🎯 Exploit Status
Exploitation requires high-privilege access and knowledge of buffer overflow techniques
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: Not available
Restart Required: Yes
Instructions:
1. Check Milesight website for firmware updates
2. Download latest firmware
3. Upload via web interface
4. Reboot router
5. Verify version update
🔧 Temporary Workarounds
Network Segmentation
allIsolate UR32L routers from untrusted networks and restrict access to management interfaces
Access Control
allImplement strict authentication and authorization controls for router management
🧯 If You Can't Patch
- Implement strict network segmentation to isolate vulnerable routers
- Monitor for suspicious HTTP requests to router management interfaces
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface or SSH: cat /etc/versionCheck Version:
cat /etc/versionVerify Fix Applied:
Verify firmware version is updated beyond v32.3.0.5📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to router management interface
- Multiple failed authentication attempts followed by successful high-privilege access
Network Indicators:
- HTTP requests with unusually long parameters to router management port
- Traffic patterns suggesting buffer overflow attempts
SIEM Query:
source="router_logs" AND (http_uri="*vtysh_ubus*" OR http_uri="*into_class_node*") AND http_request_length>1000