CVE-2020-37097
📋 TL;DR
CVE-2020-37097 allows unauthenticated attackers to access the wlencrypt_wiz.asp file on Edimax EW-7438RPn range extenders, exposing WiFi network configuration details including plaintext passwords. This affects users of Edimax EW-7438RPn devices with firmware version 1.13. Attackers can use this information to compromise the associated WiFi network.
💻 Affected Systems
- Edimax EW-7438RPn Mini
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full access to the WiFi network, enabling man-in-the-middle attacks, data interception, and lateral movement to connected devices.
Likely Case
Attackers obtain WiFi credentials and join the network, potentially accessing shared resources and monitoring network traffic.
If Mitigated
With proper network segmentation and monitoring, impact is limited to the isolated range extender network segment.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB (ID 48365). Attack requires HTTP access to the device's web interface.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://www.edimax.com/edimax/merchandise/merchandise_detail/data/edimax/global/wi-fi_range_extenders_n300/ew-7438rpn_mini/
Restart Required: No
Instructions:
No official patch is available. Consider replacing the device or implementing workarounds.
🔧 Temporary Workarounds
Block web interface access
linuxUse firewall rules to restrict access to the device's web interface (typically port 80/443).
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
Change WiFi credentials
allImmediately change the WiFi password on both the main router and range extender.
🧯 If You Can't Patch
- Replace the vulnerable device with a supported model
- Isolate the range extender on a separate VLAN with strict firewall rules
🔍 How to Verify
Check if Vulnerable:
Access http://[device-ip]/wlencrypt_wiz.asp. If it returns WiFi configuration with plaintext password, the device is vulnerable.Check Version:
Check firmware version in device web interface under System Status or similar section.Verify Fix Applied:
Attempt to access the wlencrypt_wiz.asp file. It should return an error or no sensitive data.📡 Detection & Monitoring
Log Indicators:
- HTTP GET requests to /wlencrypt_wiz.asp from unauthorized IPs
- Multiple failed authentication attempts followed by access to wlencrypt_wiz.asp
Network Indicators:
- Unusual HTTP traffic to device IP on port 80
- ARP spoofing or unusual MAC addresses on network after exploitation
SIEM Query:
source="device_logs" AND url="/wlencrypt_wiz.asp" AND NOT src_ip IN [authorized_admin_ips]