2025-02-12
When an IoT device company ceases operations, it often spins down its cloud servers. However, the subdomains used for device communications and firmware updates may become available again, leading to a potential subdomain takeover. This scenario was recently highlighted when a subscriber of a hardware security researcher registered a Microsoft Azure blob storage hostname from failed DNS requests found in Wireshark.
The traffic received was astonishing. Within 24 hours, the Blob storage instance received approximately 1.3 million requests for firmware downloads. These requests included URLs for OpenWrt base OS firmware updates and device-specific code.
Practical Steps to Mitigate Subdomain Takeover Risks
1. Monitor DNS Records Regularly:
dig +short example.com
Regularly check your DNS records to ensure no subdomains are pointing to decommissioned services.
2. Use DNS Monitoring Tools:
sudo apt-get install dnsutils
Tools like `dnsutils` can help automate DNS monitoring.
3. Secure Cloud Storage:
az storage account show --name <storage_account_name> --resource-group <resource_group>
Ensure that your cloud storage accounts are properly configured and not left exposed.
4. Implement Web Application Firewalls (WAF):
sudo apt-get install modsecurity-crs
WAFs can help detect and block malicious traffic.
5. Regularly Update Firmware:
opkg update opkg upgrade
Keep your IoT devices’ firmware up to date to mitigate vulnerabilities.
6. Conduct Security Audits:
nmap -sV -O <target_IP>
Regularly audit your network for vulnerabilities.
What Undercode Say
Subdomain takeover is a significant cybersecurity threat, especially in the context of IoT devices. When companies go out of business, they often leave behind digital footprints that can be exploited. The case of the Akita IoT defender highlights the importance of maintaining control over your digital assets, even after decommissioning services.
To mitigate these risks, it is crucial to monitor DNS records regularly. Tools like `dig` and `dnsutils` can help automate this process. Additionally, securing cloud storage and implementing Web Application Firewalls (WAF) can provide an extra layer of security.
Regular firmware updates are essential to keep IoT devices secure. Using commands like `opkg update` and `opkg upgrade` can help ensure that your devices are running the latest firmware versions. Conducting regular security audits with tools like `nmap` can also help identify and address vulnerabilities.
In conclusion, subdomain takeover is a real and present danger in the IoT landscape. By taking proactive steps to monitor DNS records, secure cloud storage, and keep firmware up to date, you can significantly reduce the risk of falling victim to such attacks. Always remember that cybersecurity is an ongoing process, and staying vigilant is key to protecting your digital assets.
For more detailed analysis, you can watch the full video here.
References:
Hackers Feeds, Undercode AI
