Network Security
Troubleshoot Expired Certificates
Table of Contents
Troubleshoot Expired Certificates
Find sites that have expired certificates so you can make informed decisions about
allowed traffic.
| Where Can I Use This? | What Do I Need? |
|---|---|
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No separate license required for decryption when using NGFWs or
Prisma Access.
Note: The features and capabilities available to you in
Strata Cloud Manager depend on your active license(s).
|
If you follow decryption best practices and
block sessions with expired certificates in a decryption profile for SSL Forward Proxy or
No-decryption, and a server presents an expired
certificate, the Next-Generation Firewall (NGFW) blocks the session.
However, if a site that you need to access for business reasons allows its
certificate to expire, connections to that site could be blocked and you may not
know why. You can use decryption logs to check for expired certificates or
certificates that will expire soon so you can be aware of the situation and take
appropriate action.
Troubleshoot Expired Server Certificates (Strata Cloud Manager)
- Filter the decryption logs for expired certificates.
- Select and select Firewall/Decryption.
- In the search field, enter the query Error Message = ‘Expired server certificate’.This query identifies servers that generate Expired server certificate errors. The NGFW 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 logs for certificates that will expire soon.
- Select and select Firewall/Decryption.
- In the search field, enter a query that identifies upcoming certificate end dates: For example, suppose today’s date is December 1, 2024, and you want to give yourself two months to evaluate and prepare in case sites don’t update their certificates, query the decryption logs for certificates that expire February 1, 2025 or earlier (Time Not After <=‘2020-01-01’)).
The Certificate End Date column shows the exact 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 rule that targets business-critical sites with expired certificates and a decryption profile that allows access to sites with expired certificates. Apply the rule exclusively to business-critical sites. As sites update their certificates, promptly remove them from the rule.
Troubleshoot Expired Server Certificates (PAN-OS)
- Filter the decryption logs for expired certificates using the query (error eq ‘Expired server certificate’).
This query identifies servers that generate Expired server certificate errors. The NGFW 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 logs () 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 logs for certificates that expire April 1, 2020 or earlier (notafter leq ‘2020/4/01’)):
The Certificate End Date column shows the exact 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 blocking 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 rule that targets sites with expired certificates that you need for business purposes. Then, create and attach a decryption profile that allows access to sites with expired certificates. Apply the rule exclusively to business-critical sites. As sites update their certificate, promptly remove them from the rule.
