The OpenSSL library is used by 4D for encryption fucntionalities such as TLS (in the Web Server, HTTP CLient, and Client-Server communication) as well as commands handling encryption like ENCRYPT BLOB.
The OpenSSL Library produces updates to the library on an irregular basis and 4D updates the version used approximately every 6 months. Sometimes, a customer may require an update to be made sooner; for this reason 4D provides instructions for updating the OpenSSL library.
When updating the OpenSSL library it is important to remember that the upgrade path must remain within the same branch. Meaning that if the version of 4D is currently using OpenSSL 1.0.2n then it would be possible to go to 1.0.2x but it would not be possible to deviate from the 1.0.2 branch. Therefore it would not be possible to upgrade to 1.0.3 or 1.1.2 on your own.