Last Updated on December 3, 2023
Mozilla Firefox verifies the certificate that helps in protecting and securing the website. Firefox stops the website connection if the validity of the certificate is not verified. The error message can display on the screen showing “Warning: Potential Security Risk Ahead”. The particular error can be viewed in Firefox by just clicking the Advanced option.
What is the Meaning of this Error Code?
A website needs to issue a certificate from the trusted Certificate Authority (CA) at the time of secure connection. It will help to ensure that the connection to which the user is associated is secure and encrypted. An error page will appear after clicking the Advanced button on the error message “Warning: Potential Security Risk Ahead”. The error code which displays on the screen is Sec_Error_Unknown_Issuer or Mozilla_Pkix_Error_Mitm_Detected.
Error Occurs on the Multiple Secure Sites
If the problem occurs on the multiple HTTPS sites which are not related to each other then it will show that some system or network interception on your connection and also inject certificates that Firefox is not trusted. Security software scanning encrypted connections are the most common cause of showing this error. The error can also occur due to malware listening and legitimate website certificate replacement. In Mozilla Firefox, a connection interception is detected which shows an error code Mozilla_Pkix_Error_Mitm_Detected.
Products of Antivirus
In the connection of Mozilla Firefox, the third-party software of antivirus can interfere. It is recommended to uninstall the software of the third-party and use the security software which is offered by Microsoft for Windows that is Windows Defender for Windows 8 and 10. You can also try to reinstall the third-party software without doing the uninstallation process but might create a problem in placing the certificates in Firefox.
The interception of the secure connections can be disabled by Avast or AVG security products. There are some steps that need to be followed:
- First, go to Avast or AVG application and open a dashboard.
- Now Go to Menu and Choose Settings, Protection, and Core shields.
- In the Core Shields click and scroll down for configure shield settings section.
- Tab on the Web Shield option.
- A box showing Enable HTTPS scanning, do uncheck it.
- Click OK for giving confirmation.
By following some steps, one can disable the interception in the secure connections by using Bitdefender security products:
- Go to the Bitdefender application and open the dashboard.
- Select Protection and further Online Threat Prevention option.
- Click OK in the settings.
- Untick the Encrypted Web Scan setting.
It is not possible to control the above-mentioned settings in the free Bitdefender antivirus. When you see some issues then the only option is to repair or remove the program for making the website connection secure.
The interception of the secure connections can be disabled on specific sites such as Google, Yahoo, and Facebook by using Bullguard:
- Open the Bullguard application dashboard.
- Go to Settings and click on enabling the Advanced view present at the top right position of the panel.
- Go to Antivirus and click on the Safe browsing option.
- Untick the Show safe results option for the websites that show an error message.
You have the option to disable and re-enable the SSL/TLS protocol by using the ESET security products.
The highly latest version of the security product is designed and upgraded by Kaspersky. It was launched in 2019 and it consists of all the solutions to error problems. The users should install the latest version of Kaspersky as it is free and comes with a current subscription. For disabling the secure connection interception, you need to follow some steps:
- Go to the Kaspersky application and open the dashboard.
- Select Settings option present at the bottom-left.
- Now Click on Additional and choose Network.
- Go to Encrypted connections scanning and tick the Do not scan encrypted connections option.
- Click OK to confirm.
- At last reboot, the computer so that changes show its effect.
Monitoring or Filtering in Corporate Networks
In the corporate areas, various traffic monitoring or filtering products are used that might stop the encrypted connections which help to replace the certificate of the website on their own and simultaneously solve the error issues on secure HTTPS sites. To ensure the perfect configuration of Mozilla Firefox, you need to contact the IT department which helps them to enable the working of the corporate networks correctly in such environments. The important certificate is present in the Firefox trust store.
The encrypted web traffic can be caused due to error message which may intercept some forms of malware.
Error Occurs on One Specific Site Only
When the issue occurs on one specific website then this error usually shows that the configuration of the webserver is not proper and appropriate. This type of error may display on some major legitimate websites such as Google, Yahoo, Facebook, etc.
Authority Issue a Certificate That Belongs to Symantec
The trust of browser vendors such as Mozilla is decreasing on the Symantec root authorities due to a high number of irregularities present in the certificates issued. The certificates issued by Symantec are no longer trusted by Firefox. For example – GeoTrust, RapidSSL, Thawte, and Verisign. The primary error that appears is Mozilla_Pkix_Error_Additional_Policy_Constraint_Failed and some other servers show the error code Sec_Error_Unknown_Issuer. The owner of the website should be contacted to inform the occurrence of the problem. The certificates need to be replaced at immediate action for the websites that are strongly affected by Mozilla Firefox.
Missing Intermediate Certificate
There are several errors that occur on a site with a missing intermediate certificate. The trusted certificate authority might not issue the website certificate by itself. The trusted authority will not provide any complete certificate chain. The website can be tested for its proper configuration by typing the address of the website into a third-party tool such as the SSL Labs test page. An appropriate intermediate certificate is missing if the returning result is “Chain issues: Incomplete”. The website owner can be contacted for informing him or her about the problem that is occurring on the website.
The error code will appear on a site with a self-signed certificate showing Error_Self_Signed_Cert. The recognized certificate authority will not issue the self-signed certificate that is why it is not trusted by default. The data of your website become safe and secure with the help of self-signed certificates but it will not tell anything about the data recipient. Self-signed certificates are the common intranet websites that are not present in the public domain.