Index: /trunk/src/VBox/Additions/linux/installer/vboxadd.sh
===================================================================
--- /trunk/src/VBox/Additions/linux/installer/vboxadd.sh	(revision 31314)
+++ /trunk/src/VBox/Additions/linux/installer/vboxadd.sh	(revision 31315)
@@ -397,4 +397,9 @@
     # And for the others, we choose a UID ourselves
     useradd -d /var/run/vboxadd -g 1 -u 501 -o -s /bin/false vboxadd >/dev/null 2>&1
+
+    # Add a group "vboxsf" for Shared Folders access
+    # All users which want to access the auto-mounted Shared Folders have to
+    # be added to this group.
+    groupadd -f vboxsf >/dev/null 2>&1
 
     # Create udev description file
Index: /trunk/src/VBox/Additions/solaris/Installer/postinstall.sh
===================================================================
--- /trunk/src/VBox/Additions/solaris/Installer/postinstall.sh	(revision 31314)
+++ /trunk/src/VBox/Additions/solaris/Installer/postinstall.sh	(revision 31315)
@@ -329,4 +329,9 @@
 fi
 
+# Add a group "vboxsf" for Shared Folders access
+# All users which want to access the auto-mounted Shared Folders have to
+# be added to this group.
+groupadd vboxsf >/dev/null 2>&1
+
 # install openGL extensions for X.Org
 if test ! -z "$xorgbin"; then