What is wildcard certificate and what are the wildcard certificate risks when applied for subdomain and multiple subdomains?
An unlimited number of subdomains under a single domain name can be secured by a website using a wildcard certificate, a form of SSL/TLS certificate. Instead of a specific subdomain like mail.example.com or shop.example.com, the certificate is granted to *.example.com.
Using a wildcard certificate has the major benefit of making it easier to maintain SSL/TLS certificates for websites with various subdomains. A single wildcard certificate can be used to secure all subdomains rather than acquiring and handling separate certificates for every one of them.
However, employing a wildcard certificate carries considerable hazards, especially if it is used across several subdomains. Among these dangers are:
- Wider attack surface: Since the same certificate is used for several subdomains, it can be simpler for an attacker to access additional subdomains if one subdomain is compromised.
- Added complexity: Using wildcard certificates can make managing and troubleshooting SSL/TLS issues more challenging, especially in complicated setups with many of subdomain.
- Less security: Compared to individual SSL/TLS certificates, wildcard certificates often offer less protection. For instance, they could not have the same level of validation as individual certificates or support the most recent encryption algorithms.
- Limited security: Wildcard certificates only offer protection for domain names’ subdomains. Attacks on the root domain or other domains are not protected from by them.