4 comment
13 min read
Mar 18, 2021

Technical SEO is a foundation of all the other optimization efforts, and if your website has security flaws, it’s highly unlikely that you can engage your visitors and make it to the top in the SERP. 

In our previous posts, we’ve discussed general website security issues and the importance of moving to HTTPS. Now, we want to cover the topic of SSL/TLS certificates and errors that might compromise information kept on your website and damage your performance in search.

What is an SSL/TLS and why it’s important

An SSL (Secure Sockets Layer) ensures the safe travel of information across networks, and TLS (Transport Layer Security) is an updated version of SSL. Both represent a standard encryption technology that secures information between a user’s browser and a website. SSL was introduced in 1995 and upgraded to TLS in 1999, catering to the growing demand for sensitive data protection. 

The SSL/TLS terms are interconnected with HTTPS (Hypertext Transfer Protocol Secure): the HTTPS connection means that the website transmits data over SSL or TLS technology.

Protocols have been continuously updated and all previous versions are considered deprecated. We’ll talk about this later when explaining the outdated SSL/TLS errors. The major thing to understand is that it’s best to use the current version of TLS as all the others are inferior to it.

How SSL/TLS impact search engine rankings

Google puts user security among the top priorities and elevates the requirements regarding SSL/TLS certificates. HTTPS has been a ranking signal since 2014. Other search engines haven’t been much vocal about how security impacts their rankings, and back in 2014, Bing even announced that it didn’t plan to rank HTTPS websites higher.

However, you shouldn’t underestimate the value of a secure protocol and encryption. Any vulnerability might get user data exposed, SSL/TLS certificate issues might lead to a website becoming unreachable, and security warnings shown by browsers might scare potential visitors away.

Detect website security issues along with 100+ other errors that may hinder your website performance.

In 2017, Google Chrome started showing the “Not secure” warning on non-HTTPS pages that would ask for sensitive information (credit card details or passwords) and a year later, it began flagging all websites that haven’t switched to a secure protocol as “Not secure.” Now, HTTPS pages account for more than 90% of the browsing time on Chrome.

Most popular browsers mark unsecure web pages with the help of the padlock icon: in Safari, you would see one only if the website is safely encrypted, and in Firefox, the strikethrough padlock signals about HTTP pages with login functionality. 

Certificate information in the Chrome browser
Connection information in Chrome

While the benefits of SSL/TLS and risks of not adopting it are on the surface, in reality, the world is far from being 100% HTTPS. The 2018 report shows that over 32% of web servers of US companies have the lowest grade for their SSL/TLS encryption and over 7% use a vulnerable and deprecated protocol.

Let’s Encrypt’s executive director explains low SSL/TLS adoption rates with the fact that the protocols are hard to manage. But there are solutions like Let’s Encrypt that help website owners big time by automating SSL/TLS certificate acquisition and management. With a variety of helpful tools at your disposal, it’s not that tricky to keep your website security in tune.

How to fix major SSL/TLS errors

When you do realize the importance of proper encryption and have an SSL/TLS certificate, it doesn’t guarantee that you won’t face any problems with it. Regularly scan your site for major SSL/TLS vulnerabilities. You can do this quickly by using the SE Ranking tool for website SEO audit.

Open the Website Audit in the left-hand navigation bar and go to the Website Security section in the Issue Report tab:

Security certificate check in SE Ranking's website audit

For a more detailed site inspection, use our website audit checklist. It includes all the basic checks you need to do. So you won’t miss anything.

Now, let’s move to the analysis of these SSL/TLS errors and possible solutions to each of them.

1. Expired website security certificate

Any SSL/TLS certificate has a limited lifespan and it keeps shrinking over the years due to ever-increasing security concerns. The validity period was decreased to five years in 2011, to three years in 2015, and to two years in 2018. Starting from September 2020, new certificates last for only 398 days (13 months). Apple was first to announce that Safari wouldn’t accept the certificates that have a longer expiration date; Google and Mozilla followed this decision shortly. 

Certificate expiration information is open to anyone in a browser:

Certificate expiration information in Safari

What happens when your SSL/TLS certificate gets expired? Your website will become unreachable, and users trying to visit it will see a warning message in their browser. This would push visitors to take a U-turn and your business can face traffic, revenue, and reputation loss.

Browser warning for a website with an expired certificate

To avoid such situations, make sure to monitor the expiration date and update the certificate on time. There are automated solutions like Let’s Encrypt or AWS Certificate Manager that help keep track of your SSL/TLS certificates, as well as monitoring tools like Sematext that send multiple alerts before the certificate expires. Many certificate issuers also provide an opportunity to set automatic renewals.

But if you do end up with an expired website security certificate, how do you fix it? You need to manually renew your certificate or purchase a new one. Each renewal or purchase validates your website’s identity and the current version of encryption. The process goes through several steps:

  • Choosing a type of certificate. Most issuing authorities provide several options for different needs from an internal network to a large-scale website. This step doesn’t apply if you’re renewing your certificate and don’t want to switch to another type (for example, it makes sense to switch to a Wildcard certificate when adding subdomains to a website). When buying a certificate, beware that there are fraudulent certificates sold online that will put your site at security risks. Learn about the issuer before the purchase. You can set CAA records to avoid untrustworthy certificate authorities. Some CAs you can trust include Digicert, GlobalSign, Sectigo, Thawte
  • Generating a certificate signing request (CSR). You need to generate a CSR from your hosting provider. The process is quite straightforward but varies depending on the web host. As a result, you will have a CRS to upload with your SSL/TLS provider and a private key file to locate on the OS you’re using. 
  • Activating and validating the certificate. You need to confirm ownership of your domain by email, CNAME record, or validation file. This process also depends on the provider so you can check up the details with your web host.
  • Verification. After you’ve installed the certificate, run an SSL/TLS check to make sure everything works correctly. Here’s an example of an online checking tool:
SSL/TLS checker

If you’re switching to HTTPS at this point, and it’s the first time the certificate is installed, you need to redirect the website’s HTTP traffic to its HTTPS version and add the secure version to webmaster tools. Learn more about these technicalities from our post on moving a website to HTTPS.

To avoid certificate expiration in the future, don’t ignore expiration notifications and for your convenience, find a certificate management solution. 

2. Outdated security protocol

Encryption technologies evolve over the years, and so do security risks and potential hacker attacks. This is one of the reasons why the SSL/TLS certificate lifecycle is shortening and also why the versions are updated and the previous ones announced deprecated and unsafe. 

Since TLS was introduced as an upgrade to SSL (version 3.0 at that time), any TLS version is more secure than SSL. The latest version of the protocol is TLS 1.3, released in 2018: it has an improved cryptographic algorithm and requires only one round-trip for the handshake (which means that the browser connects to your website’s server easier). 

Starting from 2020, all the major browsers display warnings for websites that use TLS 1.0 or 1.1 and prevent users from accessing. With that said, you might want to use the current TLS version and disable the older ones.

There are multiple ways to check what protocol version a website uses:

  • In the Security tab in Chrome DevTools:
Checking the protocol version in Chrome DevTools
  • In a third-party checker. Some of them will provide information on what TLS and SSL versions are enabled:
Checking the protocol version and all enabled versions

To enable the latest version of TLS, first make sure your website is configured to use it. Run an SSL server test and check the Configuration section in the results:

Checking website's configuration in a SSL server test

Then, check up with your hosting provider and learn what you need to do to enable the latest protocol version. Generally, you’ll need to specify the right protocol in your server’s configuration file.

For example, if your site runs on a Nginx server, you’ll have to edit the nginx.conf file and specify the TLS version you’ve installed. Add the upgraded protocol and disable all deprecated versions. The configuration line will look like this:

ssl_protocols TLSv1.2 TLSv1.3;

If it turns out your site doesn’t support TLS 1.2 or 1.3, you’ll need to contact the web host and possibly upgrade to another plan. 

3. Certificate name mismatch

A certificate name mismatch usually occurs when the domain name in the SSL/TLS certificate doesn’t match what a user has entered in the browser. Users will see a warning:

Warning for a website with certificate name mismatch

Multiple reasons stand behind an SSL certificate domain name mismatch error:

  • Your website is being accessed via an internal domain name that isn’t specified in the certificate (for example, you input yourwebsite.localhost and your certificate only has yourwebsite.com). How to fix a SSL certificate name mismatch error? By getting a SAN (Subject Alternate Name) certificate that allows including multiple hostnames under a single certificate. Note that SAM is not available in all plans with different certificate authorities.
  • Your website can be assessed with and without “www” but the certificate has only one domain name specified. It’s important to decide on whether to use “www” with a domain name, forward all traffic to a chosen version, and get an SSL/TLS certificate according to the chosen version (with or without “www”). We give more details on how this impacts your SEO in our article on www and non-www domain names. A certificate with SANs is also a solution here. 
  • Your website shares the IP address with others and doesn’t have a separate protocol. Most resources don’t need a dedicated IP (unless they send a lot of emails) and a shared one comes with a lower price. If you have a shared IP, you need to indicate your domain name in the protocol’s extension called SNI (Server Name Indication). With SNI, the server will select a TLS certificate unique to a given hostname and a corresponding private key instead of going for a default certificate shared across several sites.
  • Your website’s hosting provider has pre-configured settings that force their SSL/TLS on your domain name. To solve this, you need to contact the provider and let them replace their certificate with yours, or consider switching to another provider. 

You can verify what domain names are protected under your SSL/TLS certificate in an online checking tool. For example:

Checking domains names included in the protocol

4. Outdated encryption algorithm

When a user accesses a website, their browser authenticates the TLS certificate through a process called a handshake. Cipher suites, which are algorithms that encrypt each connection, play a crucial role in the beginning of this process: the browser communicates which cipher suites it supports and the server responds with the most secure one. If the cipher suite configured in the server isn’t secure enough, the browser will issue an “obsolete cryptography” warning.

A cipher suite includes several ciphers, each representing a certain cryptographic function. Before TLS 1.3, the best recommended combination comprised of four ciphers:

  • An algorithm for key exchange between the server and the browser (ECDHE)
  • A digital signature that helps authenticate the certificate (ECDSA)
  • A cipher for secure data transfer (AES-256-GCM)
  • An algorithm for message authentication (SHA384)

The TLS 1.3 cipher suite consists of the two latter ciphers only—this version doesn’t support outdated key exchange and authentication algorithms by default. While TLS 1.2 can still be used for a secure connection, the ciphers accepted by this version vary in quality, which can lead to vulnerability to cyber attacks. With the latest version of TLS, you get less variability in ciphers and the whole handshake process gets faster, simpler, and safer.

You need to make sure you’re not using outdated cryptographic algorithms. To learn what cipher suites are enabled on your server, you can run an SSL/TLS server test online:

Checking cipher suites supported by SSL/TLS

If you find out that weak ciphers are still supported by your TLS, you need to disable them in the server configuration. It also makes sense to set a cipher order preference to indicate which ciphers browsers will prioritize when connecting to your website. To do so, first check the security ratings of ciphers and cipher strings.

Secure your website like a pro

The simple truth is, you can’t go without solid website security measures, and one of the major aspects of protecting your site from cyber attacks and data exposure is proper SSL/TLS configuration and management. We recommend that you update to the latest TLS version, set alerts about the certificate expiration date, enable the most secure cryptography, and regularly scan your protocol for vulnerabilities. Cyber threats keep evolving so make sure you keep track of how safely users connect to your website.

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  1. Thanks for the post! With certificate validity getting reduced all the time, it’s definitely better to find a decent management solution!

    1. Thanks for your comment, Max! We also are in favor of certificate management solutions.

  2. I’m thinking that TLS 1.2 will be announced to be insecure pretty soon. The difference is significant

    1. Thanks for your comment, Lesley! Even though TLS 1.3 is your best choice and we do recommend switching to it, the 1.2 version might still be enough for protecting your website.

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