This subdomain has been taken over by Cyderes to demonstrate a subdomain takeover vulnerability. This is a controlled demonstration by our security team to show stakeholders how we detect and respond to such vulnerabilities.
Subdomain Takeover Demonstration
This page demonstrates how a subdomain takeover vulnerability occurs when a DNS record points to a third-party service (like GitHub Pages) but the resource on that service has been deleted or deprovisioned.
What is a Subdomain Takeover?
A subdomain takeover occurs when a subdomain (e.g., blog.cyderes.com) has a DNS record pointing to a third-party service (like GitHub Pages, Heroku, AWS S3), but the resource on that service has been deleted or deprovisioned.
This creates a "dangling pointer" - DNS record exists, but it points to nothing. An attacker can then register a new resource with the same name on the third-party service, effectively taking control of the subdomain.
Why Is This Dangerous?
Subdomain takeovers pose significant security risks:
Phishing Attacks
Attackers can host convincing phishing pages on your trusted domain, tricking users into revealing credentials or sensitive information.
Malware Distribution
The compromised subdomain can be used to distribute malware to visitors who trust your domain.
Cookie Theft
If the subdomain shares cookies with the main domain, attackers could potentially steal session information.
Brand Damage
Attackers can deface the website with inappropriate content, causing public embarrassment and loss of trust.
How to Fix This Vulnerability
The fix for a subdomain takeover is straightforward:
Remove the DNS Record
Delete the CNAME or A record for the vulnerable subdomain from your domain's DNS settings.
Reclaim the Resource
Create a new, legitimate resource on the third-party service to re-establish control over the subdomain.
Implement Monitoring
Set up automated monitoring to detect dangling DNS records before they can be exploited.
Contact Cyderes
Is your organization secure against subdomain takeovers and other vulnerabilities? Contact Cyderes today for a comprehensive security assessment.
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