Unfortunately rohitkumar1609, by granting Read access to the folder connection just stops users from updating the folder connection definition. A user can still use this connection file to read or write to a QVD in the underlying folder.
The problem appears to be that the Qlik service account has read/write privs on the underlying directory. Ideally, we need to be able to have a second service account that only has read access to the underlying directory, and have the connection execute under that service account. We are not sure how this might be achieved.