Certificates and TLS settings are part of your attack surface. Expired certificates can cause outages. Weak TLS can put encrypted traffic at risk. Forgotten certificates can also reveal assets that your team no longer tracks. Continuous discovery helps find these issues before attackers do.
Why certificates and TLS matter for security
Certificates and TLS can seem like routine technical tasks. Install a certificate, enable HTTPS and move on.
The reality is more complex. Certificates and TLS settings can create security risks when teams lose track of them. They can also reveal assets that are no longer in an organisation’s inventory.
Three issues deserve close attention:
- Expired certificates
- Weak or incorrect TLS settings
- Forgotten certificates linked to unknown assets
Each creates a different risk. Together, they make certificate management an important part of attack surface management.
Expired certificates
Certificate expiry is the most familiar problem.
When a certificate expires, browsers can show security warnings. Some services may also stop working. These problems can cause outages and damage user trust.
An expired certificate can also point to a wider process problem. If nobody noticed the expiry, the organisation may not have a clear view of its certificates.
One missed certificate can also indicate that other certificates are not being tracked. Those certificates could be close to expiry or linked to systems that nobody monitors.
Weak or misconfigured TLS
TLS protects data as it travels between users and services. Its effectiveness depends on how the organisation configures it.
Old protocols, weak ciphers and incorrect settings can reduce the protection TLS provides. In some cases, attackers may be able to intercept or alter traffic.
The risk can be difficult to spot. The website can still show HTTPS. The connection can still appear secure. Users may see the familiar padlock and assume everything is protected.
A weak TLS configuration can therefore create a false sense of security. The problem only becomes clear when someone checks the underlying configuration.
Forgotten certificates can reveal unknown assets
Certificates can also provide clues about your wider attack surface.
A certificate is usually linked to a specific domain, subdomain or service. Finding a certificate for an asset that nobody recognises can reveal something your security team has lost track of.
For example, a certificate might point to:
- An old subdomain
- A forgotten service
- A system that should have been removed
- A cloud resource outside the current inventory
- A development environment that remains online
These assets can create security risks when nobody monitors or maintains them.
Certificate discovery can therefore do more than identify certificate problems. It can help uncover assets that have disappeared from your inventory.
Why certificates are easy to lose track of
Most organisations use certificates across many systems and services. Different teams may manage different domains, applications and cloud resources.
Over time, certificates are issued, renewed and replaced. Services are also created and removed. Without central visibility, it becomes difficult to maintain an accurate record.
This can lead to certificate sprawl.
Teams may not know:
- How many certificates they have
- Which assets each certificate covers
- Which certificates are close to expiry
- Which TLS settings are weak
- Which certificates point to unknown assets
You cannot manage risks that you cannot see. That makes visibility the first step in reducing certificate and TLS exposure.
Finding certificate risks continuously
Certificate risks change as your environment changes.
A new service can introduce a certificate. A certificate can approach its expiry date. A new configuration can weaken TLS. An old certificate can reveal an asset that nobody remembers.
For that reason, a one-time certificate review is not enough.
Continuous discovery gives security teams a current view of certificates and the assets connected to them. It can help identify certificates that are:
- Close to expiry
- Linked to unknown assets
- Associated with weak TLS settings
- Connected to services that should no longer be exposed
This turns certificate management from a periodic task into an ongoing part of security monitoring.
Turning certificate discovery into action
Finding a certificate does not reduce risk on its own. Teams still need to investigate what they find and decide what action to take.
An expired certificate may need renewal. A weak TLS configuration may need to change. A forgotten asset may need to be removed or brought back under security controls.
Validation adds another layer. It can help determine whether an identified exposure is genuinely exploitable and how it could affect the organisation.
This helps security teams focus on the issues that create the greatest real-world risk.
Why continuous visibility matters
Your external attack surface does not stay the same.
Certificates are issued and renewed. Services move. Cloud resources appear. Old systems remain online. New configurations introduce new risks.
A review from several months ago cannot show everything that exists today.
Continuous discovery keeps certificate and TLS exposure in view as the environment changes. It also helps security teams find unknown assets before attackers discover them.
To bring certificates and the assets they reveal into view, explore our attack surface management platform. You can also read about external attack surface management and how it uncovers unknown internet-facing assets.
For TLS security guidance, refer to recognised secure TLS configuration standards and best practices.
Frequently asked questions
Why are certificates part of the attack surface?
Certificates can reveal assets, expose weak TLS settings and create operational risks when they expire. A certificate linked to an unknown system can also reveal an asset that your security team no longer tracks.
What happens when a certificate expires?
An expired certificate can trigger browser security warnings and cause some services to stop working. It can also indicate gaps in certificate management and visibility.
How does weak TLS create security risk?
Weak or outdated TLS settings can reduce the protection provided by encrypted connections. In some cases, attackers may be able to intercept or alter traffic.
How can forgotten certificates reveal unknown assets?
Certificates are linked to domains, subdomains and services. A certificate for an asset that nobody recognises can reveal an old, forgotten or unmanaged system.
How can organisations find certificate risks?
Continuous attack surface discovery can identify certificates, their associated assets and potential TLS issues. Teams can then investigate, remediate and validate the exposures that create genuine risk.
