Browsers do not trust all types of SSL certificates. After some websites deploy self-signed certificates, the browser will pop up warning messages constantly, which will affect the user experience.
Second, self-issued SSL certificates are vulnerable to attacks by SSL intermediaries.
When users visit websites with self-signed SSL certificates, they will turn a blind eye to the warnings of the browser and gradually form the habit of ignoring the warnings of the browser, which will undoubtedly give the middleman an opportunity to be attacked by the middleman.
Third, the SSL certificate issued by itself is easy to be forged or forged, and it is easy to be used by fraudulent websites.
Due to the issuance of SSL certificates, you can issue them at any time without supervision. If your website uses its own SSL certificate, hackers can forge the same certificate as your website and use it for fishing.
Fourth, there is no accessible self-signed SSL certificate revocation list.
In order to ensure the normal operation of SSL certificate, the browser needs to check whether the SSL certificate status is expired or revoked. The certificate must contain a certificate revocation list that the browser can access. If the browser can't confirm the revocation status of SSL certificate in time, once the certificate is lost or stolen, it will be more likely to make users suffer losses.
Fifthly, SSL certificate has a long validity period since it was issued, and the longer it takes, the easier it is to be cracked.
Since the production cost of self-signed SSL certificate is not specified, its validity period is as long as 5 years, and some even as long as 20 or 30 years, so hackers have enough time to crack your password.