CVE-2023-25102
📋 TL;DR
This vulnerability allows attackers with high privileges to execute arbitrary code on Milesight UR32L routers by sending specially crafted HTTP requests that trigger buffer overflows in the vtysh_ubus binary. It affects users of the UR32L router running version v32.3.0.5, potentially leading to full system compromise.
💻 Affected Systems
- Milesight UR32L
📦 What is this software?
Ur32l Firmware by Milesight
⚠️ Risk & Real-World Impact
Worst Case
An attacker gains full remote control of the router, enabling data theft, network disruption, or use as a pivot point for further attacks.
Likely Case
Privileged attackers exploit the vulnerability to execute arbitrary commands, potentially modifying router configurations or installing malware.
If Mitigated
With proper access controls and network segmentation, impact is limited to isolated router compromise without broader network access.
🎯 Exploit Status
Exploitation requires high privileges and crafting specific HTTP requests; no public proof-of-concept is known as of the provided references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: No vendor advisory URL provided in the references.
Restart Required: No
Instructions:
Check the Milesight vendor website for firmware updates addressing CVE-2023-25102 and apply the latest patch if available.
🔧 Temporary Workarounds
Restrict HTTP Access
allLimit HTTP access to the router's management interface to trusted IP addresses only.
Use firewall rules to block external HTTP access to the router (e.g., iptables -A INPUT -p tcp --dport 80 -j DROP for Linux-based systems).
🧯 If You Can't Patch
- Isolate the router in a segmented network to limit potential lateral movement.
- Monitor for unusual HTTP requests or privilege escalation attempts on the router.
🔍 How to Verify
Check if Vulnerable:
Check the router firmware version via the web interface or CLI; if it is v32.3.0.5, it is vulnerable.Check Version:
In the router CLI, run 'show version' or check the web interface under System > Firmware.Verify Fix Applied:
After updating, verify the firmware version is no longer v32.3.0.5 and test for buffer overflow via controlled HTTP requests.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP POST requests to router endpoints, especially with long parameters in hub_ip or hub_gre_ip fields.
Network Indicators:
- Spikes in HTTP traffic to the router's management IP on port 80 or 443.
SIEM Query:
Example: 'source_ip=router_management_ip AND http_method=POST AND (uri CONTAINS "set_dmvpn" OR user_agent="malicious")'