See the “Build Dependency Management” section in the C++ Developer Documentation.
There is a convenient script that update versions in versions.txt to the latest version automatically. You can use it like the following:
cpp/thirdparty/update.rb PRODUCT_PATTERN1 PRODUCT_PATTERN2 ...
For example, you can update AWS SDK for C++ related products' versions by the following command line:
cpp/thirdparty/update.rb "AWS*" "S2N*"