InfoPath automatically redirects user requests for sites that have not been upgraded to the temporary URL if it is located on the local intranet, but blocks them if the temporary URL is located elsewhere. InfoPath will prompt users before redirecting forms or form templates to another intranet site.
If this restriction is relaxed, all requests to sites that have not been upgraded will be redirected to their targets, regardless of location. This functionality could cause requests made to a secure site to be redirected to an unsecured one (for example, requests to an intranet site could be redirected to an unencrypted Internet site), causing sensitive information to be at risk.
Set the policy value for User Configuration -> Administrative Templates -> Microsoft InfoPath 2010 -> Security -> 'Control behavior for Microsoft SharePoint Foundation gradual upgrade' to 'Enabled (Block all redirections)'.
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Information Integrity.This control applies to the following type of system Windows.