Configuring a web server with a wildcard certificate for *.companyname.com leads to a certificate error. What is the MOST likely cause?

Configuring a web server with a wildcard certificate for *.companyname.com leads to a certificate error. What is the MOST likely cause?

• A. Certificate misconfigured
• B. Certificate expired
• C. Certificate revoked
• D. Certificate not signed

Answer: (A)

Wildcard certificates cover only one level of subdomains, not the apex domain itself. A certificate issued for *.companyname.com will be valid for hostnames like www.companyname.com or shop.companyname.com, but not for companyname.com. If the web server presents this wildcard certificate when a user reaches the base domain, the hostname in the URL doesn’t match the certificate’s name, causing a certificate error. That mismatch is a signs of misconfiguration in how the certificate is meant to cover the domain. Expired, revoked, or unsigned certificates would produce different errors and wouldn’t be tied to the specific root-domain mismatch. To fix it, include the base domain in the certificate (as a SAN) or install a separate certificate for companyname.com, or adjust the server to present appropriate certificates for each hostname.

Wildcard certificates cover only one level of subdomains, not the apex domain itself. A certificate issued for *.companyname.com will be valid for hostnames like www.companyname.com or shop.companyname.com, but not for companyname.com. If the web server presents this wildcard certificate when a user reaches the base domain, the hostname in the URL doesn’t match the certificate’s name, causing a certificate error. That mismatch is a signs of misconfiguration in how the certificate is meant to cover the domain. Expired, revoked, or unsigned certificates would produce different errors and wouldn’t be tied to the specific root-domain mismatch. To fix it, include the base domain in the certificate (as a SAN) or install a separate certificate for companyname.com, or adjust the server to present appropriate certificates for each hostname.