Sharing cookies across different domains and different applications (classic ASP and ASP.NET)

Solution 1:

No, there isn't.

The issue is the cross domain one, rather than the asp.net/classic asp and is security reasons.

If the domains are subdomains you can share the cookies, provided you use a cookie path that both can access (ie. for the domain sub.example.com you can read and write cookies using the example.com domain).

Solution 2:

You can share cookies via some behind the scenes communication between servers, or through querystrings.

Both are ill advised, unless the information in the cookies is harmless (but be aware that harmless looking data quite often isn't actually harmless).

Native support for accessing cookies is not possible cross domain, and probably will never be for security reasons.