Using NSAllowsArbitraryLoads appears to be a temporary workaround. But it probably won't be available at some point.
However, I was able to get things working with a TLS 1.0 server (YOUR_HOST.COM) by doing the following:
Take special note of the "NSTemporaryExceptionRequiresForwardSecrecy" flag. It needs to be turned OFF.
| <key>NSAppTransportSecurity</key> |
| <dict> |
| <key>NSExceptionDomains</key> |
| <dict> |
| <key>YOUR_HOST.COM</key> |
| <dict> |
| <key>NSIncludesSubdomains</key> |
| <true/> |
| <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key> |
| <true/> |
| <key>NSTemporaryExceptionMinimumTLSVersion</key> |
| <string>1.0</string> |
| <key>NSTemporaryExceptionRequiresForwardSecrecy</key> |
| <false/> |
| </dict> |
| </dict> |
| </dict> |