Hello,
This is cedar-apple rust, which is a fungal disease that relies on both cedar and apple trees to grow. This disease occurs on all trees in the Cupressaceae family, which includes cedars, junipers, and cypress; apple trees that are alternate hosts include trees in the Rosaceae family including crabapples, etc.. The article below contains a comprehensive description of the fungal pathogen. 
https://extension.umn.edu/plant-diseases/cedar-apple-rust

There is no treatment for the disease. And repeated infections may weaken or kill a tree. You may choose to replace the tree in the Cupressaceae with a disease resistant variety. 

So, not good news. Please let me know if you have any questions. 

Thank you,
-Julie