Troubleshoot Expired Certificates

Filter the Decryption log for expired certificates using the query
(error eq ‘Expired server certificate’)
.
This query identifies servers that generate
Expired server certificate
errors. The firewall blocks access to these servers because of the expired certificate.
(
Optional
) Double-check the certificate expiration date at the Qualys SSL Labs site.
Enter the hostname of the server (
Server Name Identification
column of the Decryption log) in the
Hostname
field and
Submit
it to view certificate information for the host.
Filter the Decryption log (
Monitor
Logs
Decryption
) for certificates that will expire soon using a query that identifies upcoming certificate end dates.
For example, if today’s date is February 1, 2020 and you want to give yourself two months to evaluate and prepare in case sites don’t update their certificates, query the Decryption log for certificates that expire April 1 2020 or earlier (
notafter leq ‘2020/4/01’)
):
The
Certificate End Date
column shows the eact date on which the certificate expires.
Determine the action to take for sites with expired certificates.
If you don’t need to access the site for business purposes, the safest action is to continue to block access to the site.
If you need to access the site for business purposes, take one of the following actions:
Contact the administrator of the site with the expired certificate and notify them that they need to update or renew their certificate.
Create a Decryption policy that applies only to the sites with expired certificates that you need for business purposes and a Decryption profile that allows sites with expired certificates. Do not apply the policy to any sites that you don’t need for business purposes. When a site updates its certificate, remove it from the policy.