Imagine you’re on the Death Star (I) engineering team. There’s a problem to solve–there’s no way to vent the heat generated by the massive internal engine without building an exhaust port directly to space.
“Surely no one will find this tiny vulnerability,” you think. “There’s no way an intrepid Jedi will fly in on an X-wing and destroy everything I worked so hard to build.”
Now imagine you’re on the Death Star (II) engineering team. The first order of business? Fixing that exhaust port problem from the start, most likely, and any other attack surface vulnerability that could jeopardize the core reactor, the critical infrastructure upon which all of the empire’s ambitions rely.
When it comes to PKI in your organization, the flawed exhaust port is a simple misconfiguration or design flaw, like a self-signed certificate that makes it out of testing.
There are many instances in which self-signed certificates might seem like the most convenient option, but they quickly become a security liability when mismanaged, or worse, deployed in production environments.
Not only do self-signed certificates lack the validation offered by Certificate Authorities (CAs), but improper certificate management practices leave security gaps when combined with other elements of poor PKI hygiene, such as lax key storage.
Instead of leaving self-signed certs as low-hanging fruit for bad actors, take advantage of an automated, centralized certificate lifecycle management solution to minimize risks and protect your organization.
Certificates You Can Self-Sign
In certain situations, self-signed certificates serve a useful purpose within an organization’s infrastructure: they offer a quick, cost-effective way to support SSL/TLS functionality without requiring CA infrastructure. Proceed with caution, however; these self signed certificates should be limited to very specific, codified internal uses to avoid the security risks associated with unvalidated / unvalidated certificates.
Development and testing environments
Self-signed certificates allow developers in testing environments to simulate SSL/TLS functionality quickly and at no cost, enabling teams to test secure connections and encryption without involving a CA. These environments should be isolated from public networks and contain only sanitized test data, mitigating the need to maintain a public trust chain or your organizations private trust chain. Here’s the catch: it’s still essential to maintain authority and control over these types of certificates to avoid their migration into production environments by accident.
Internal services and networks
For select internal tools, intranet sites, and applications strictly accessed by authorized users, self-signed certificates may also be acceptable. In a controlled environment where external users and devices are unable to access internal resources, the absence of a trusted CA signature has minimal impact. Yet, even for internal use, self-signed certificates must be carefully managed; certificate expiration or inadvertent exposure to the public are still potential issues. However, it’s still recommended to use an internal private PKI over a self signed certificate if available.
Short-term or temporary solutions
When a certificate is needed for a short-term project or limited-duration application, self-signing might be the most straightforward option. In situations where a project will be used in-house or privately for a brief, specific time period, self-signed certificates offer a quick way to establish secure connections. As with each of the previous examples, these types of certificates should still be subject to certificate lifecycle management practices to safely decommission them when their use is exhausted.
As with many elements of cybersecurity (generally) and PKI (specifically), the use of self-signed certificates in your organization fall under risk management. With the right authority and maintenance, self-signed certificates can be a fast, handy solution; without a comprehensive CLM, these handy certs can quickly turn a useful tool into a devastating weakness.
Certificates You Should NOT Self-Sign
Most certificates should not be self-signed. Low risk is not the same as no risk; self-signed certificates fail to meet compliance standards, often are poorly minted with extensions asserted, are easy for bad actors to spoof, and cannot be trusted in many environments due to the fluid nature of most enterprise networks trying to get a new certificate pushed to all the trust stores.
In the case of public-facing applications, client-oriented services, code signing, and production environments, certificates issued by a trusted CA are essential for security, trust, and a smooth user experience.
Public-facing websites (SSL/TLS certificates)
On the internet, certificates from publicly trusted CAs are critical for secure, verifiable connections. Browsers and other clients do not recognize self-signed certificates as legitimate, greeting visitors with warnings that the site connection is “not secure.” These warnings erode user trust, detract from user experience, and discourage users from engaging with the website for their own protection. More importantly, self-signed certificates on public sites create an opportunity for in man-in-the-middle attacks, in which malicious actors intercept and manipulate data sent between the website and its visitors.
Recommendation: It’s a best practice to use CA-issued SSL/TLS certificates for public websites to protect against impersonation and maintain user confidence in your site (and, by extension, your brand). These types of certificates have short expiration windows; with a centralized CLM, you can automate the issuance, renewal, and revocation processes to save time and prevent human error.
Client-facing apps and services
Any application or service that interacts with clients or external users should use publicly trusted certificates. When client applications, browsers, or APIs communicate over HTTPS or other secure protocols, self-signed certificates trigger security warnings if they’re not rejected outright. This disruption of connectivity impacts trust, with clients perceiving the service as insecure or unprofessional. Moreover, if a self-signed certificate is used and bypassed in these settings, user data may be at risk from potential attackers who could exploit the lack of trusted verification.
Recommendation: Certificates issued by a trusted CA protect your clients from insecurity warnings and enable a consistent, secure connection to the apps and services they need.
Code signing certificates
These certificates validate the authenticity of software and verify that it hasn’t been tampered with since it was signed, indicating the transition from “test” to “production” environment. Most operating systems and application stores don’t accept self-signed code, as these provide no assurance of the developer’s identity. Like browsers, if a self-signed certificate is used to sign code, users are likely to receive warnings indicating the software is from an untrustworthy source, creating hesitation and potential security concerns.
Recommendation: Use CA-issued signing certificates to avoid security alerts and facilitate smooth installations, maintaining user trust in the software.
Production environments
The goal of development and testing is to get to the production environment, in which your application, software, or service is externally exposed. Production demands a high level of reliability, visibility, and security; even test environments that connect to production resources often need to establish an elevated level of trust to reduce security risks. Using self-signed certificates in production—or testing environments that mirror production—introduces unnecessary vulnerability, increasing the risk of operational disruptions if certificates expire or become compromised.
Recommendation: Use authoritative, CA-issued certificates for production environments such as the corporate trusted PKI for internal use cases or a publicly trust CA for external user access use cases.. A trusted CA should offer scalable solutions that provide these types of certificates on demand, effectively eliminating the barrier of issuing CA-signed certs for internal resources. For added security, use trusted certificates wherever possible.
Eliminate the need for self-signed certs with PKIaaS
Self-signed certificates might offer a quick fix for small teams or low-risk internal applications, but as your organization scales and digital operations grow more complex, they become a liability – introducing vulnerabilities and creating management headaches.
With Keyfactor’s PKI-as-a-Service, you can eliminate the need for self-signed certificates entirely. Our certificate automation and centralized management simplify issuance, expiration tracking, and renewal across all your digital assets. The result? Efficient, scalable, and secure PKI that evolves with your organization.
Don’t just take our word for it. Keyfactor earned the #1 spot in the 2024 Frost Radar™ report for Growth and Innovation among PKIaaS vendors. Security teams that face mounting pressure to protect critical systems turn to Keyfactor for a cloud-first approach that delivers PKI on demand.
Close the exhaust port and secure your Death Star – err, organization – with professionally managed PKI infrastructure that leaves nothing to chance. Build user trust, protect your systems, and stay ahead of tomorrow’s challenges with Keyfactor.
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