diff -Nru usb-creator-0.2.28/bin/usb-creator-helper usb-creator-0.2.28.1/bin/usb-creator-helper
--- usb-creator-0.2.28/bin/usb-creator-helper	2011-01-26 09:39:11.000000000 +0000
+++ usb-creator-0.2.28.1/bin/usb-creator-helper	2011-04-28 15:54:38.000000000 +0100
@@ -195,6 +195,7 @@
     @dbus.service.method(USBCREATOR_IFACE, in_signature='s', out_signature='',
                          sender_keyword='sender', connection_keyword='conn')
     def UnmountFile(self, device, sender=None, conn=None):
+        self.check_polkit(sender, conn, 'com.ubuntu.usbcreator.mount')
         popen(['umount', device])
     
     @dbus.service.method(USBCREATOR_IFACE, in_signature='s', out_signature='',
diff -Nru usb-creator-0.2.28/dbus/com.ubuntu.usbcreator.policy.in usb-creator-0.2.28.1/dbus/com.ubuntu.usbcreator.policy.in
--- usb-creator-0.2.28/dbus/com.ubuntu.usbcreator.policy.in	2009-10-22 01:38:26.000000000 +0100
+++ usb-creator-0.2.28.1/dbus/com.ubuntu.usbcreator.policy.in	2011-04-28 15:54:09.000000000 +0100
@@ -14,7 +14,7 @@
     <defaults>
       <allow_any>no</allow_any>
       <allow_inactive>no</allow_inactive>
-      <allow_active>yes</allow_active>
+      <allow_active>auth_admin_keep</allow_active>
     </defaults>
   </action>
   <action id="com.ubuntu.usbcreator.format">
@@ -23,7 +23,7 @@
     <defaults>
       <allow_any>no</allow_any>
       <allow_inactive>no</allow_inactive>
-      <allow_active>yes</allow_active>
+      <allow_active>auth_admin_keep</allow_active>
     </defaults>
   </action>
   <action id="com.ubuntu.usbcreator.image">
@@ -32,7 +32,7 @@
     <defaults>
       <allow_any>no</allow_any>
       <allow_inactive>no</allow_inactive>
-      <allow_active>yes</allow_active>
+      <allow_active>auth_admin_keep</allow_active>
     </defaults>
   </action>
   <action id="com.ubuntu.usbcreator.mount">
@@ -41,7 +41,7 @@
     <defaults>
       <allow_any>no</allow_any>
       <allow_inactive>no</allow_inactive>
-      <allow_active>yes</allow_active>
+      <allow_active>auth_admin_keep</allow_active>
     </defaults>
   </action>
 </policyconfig> 
diff -Nru usb-creator-0.2.28/debian/changelog usb-creator-0.2.28.1/debian/changelog
--- usb-creator-0.2.28/debian/changelog	2011-01-31 14:41:40.000000000 +0000
+++ usb-creator-0.2.28.1/debian/changelog	2011-04-28 15:55:01.000000000 +0100
@@ -1,3 +1,9 @@
+usb-creator (0.2.28.1) natty-security; urgency=low
+
+  * Guard UnmountFile with PolicyKit (LP: #771553).
+
+ -- Evan Dandrea <ev@ubuntu.com>  Thu, 28 Apr 2011 15:54:47 +0100
+
 usb-creator (0.2.28) natty; urgency=low
 
   * Fix showing a partitioning when it appears before the partition