Can download a copy even with View Only permissions

Question

We have a weird bug in which Excel Services allows users with View Only permissions to download files even without permissions to do so:

At first, you might think that this is a problem with permissions. However, we checked permissions many times and I can assure you that users are assigned nothing but View only. The evidence of this is that users don't have a "download a copy" button in the list view:

We did not change permission levels for View Only:

Here is what we see when clicking "Check permissions" on the File:

As you can see, there are no permissions other than View only.

We have 3 environments with SharePoint 2010 with different updates and there is only one farm (14.0.6126.5000) that is afflicted by this problem. Other farms, even with much older versions do not have this problem even though they are almost exact replicas of each other.

We have also checked this scenario on SharePoint 2013, but we could not reproduce this bug.

We were thinking about installing updated on SharePoint. But:

• Other farms with older versions do not have this problem
• There is no mention of this problem in any SharePoint updates.
• Installing updates is a very slow process in our customer's environment and it might take weeks. We only have a couple of days to fix it.

We will be very grateful if someone can help us to fix or troubleshoot this problem.

Additional information

• SharePoint 2010 version with a bug: 14.0.6126.5000
• We use Excel Services, not Web Apps. Web apps not even installed

Answer 1

We have managed to fix this problem by recreating SharePoint Web application. This is a very dirty fix, but it worked.