Everyone that is currently running FogBugz 6.x is requested to please upgrade to 6.1.13 immediately.  This fix is a security fix and is supplied to all customers.  You can download the latest version from https://shop.fogcreek.com with your order number and email address.

http://fogcreek.com/FogBugz/KB/releaseNotes/WhatsNewInFogBugz6.1.13.html

• Security Fix, applies to FogBugz versions 6.0.0 through 6.1.11
  A security vulnerability in FogBugz API versions 3 and 4 allowed registered users to view and edit some information that they did not have permissions on. It is highly recommended that all customers using FogBugz 6.0 upgrade to the latest version.
• Improved error handling and error recovery in the FogBugz Maintenance service (heartbeat)
• Better install support for Gentoo and Solaris
• Fixed a bug that was causing the screenshot tool to fail for PHP FogBugz
• Fixed intermittent SQL errors when using filters with sorted columns
• Sped up link creation in wiki
• Fixed timeout bug during FogBugz upgrade of MySQL databases