diff -Npur blender-2.61.orig/source/blender/blenkernel/intern/blender.c blender-2.61/source/blender/blenkernel/intern/blender.c
--- blender-2.61.orig/source/blender/blenkernel/intern/blender.c	2011-12-20 20:47:10.884735950 +0100
+++ blender-2.61/source/blender/blenkernel/intern/blender.c	2011-12-20 20:47:58.500735116 +0100
@@ -144,6 +144,7 @@ void initglobals(void)
 	G.f |= G_SCRIPT_AUTOEXEC;
 #else
 	G.f &= ~G_SCRIPT_AUTOEXEC;
+	G.f |= G_SCRIPT_OVERRIDE_PREF;  /* Disables turning G_SCRIPT_AUTOEXEC on from user prefs */
 #endif
 }
 
diff -Npur blender-2.61.orig/source/blender/makesrna/intern/rna_userdef.c blender-2.61/source/blender/makesrna/intern/rna_userdef.c
--- blender-2.61.orig/source/blender/makesrna/intern/rna_userdef.c	2011-12-20 20:47:10.891735952 +0100
+++ blender-2.61/source/blender/makesrna/intern/rna_userdef.c	2011-12-20 20:50:32.755732385 +0100
@@ -114,9 +114,17 @@ static void rna_userdef_show_manipulator
 
 static void rna_userdef_script_autoexec_update(Main *UNUSED(bmain), Scene *UNUSED(scene), PointerRNA *ptr)
 {
-	UserDef *userdef = (UserDef*)ptr->data;
-	if (userdef->flag & USER_SCRIPT_AUTOEXEC_DISABLE)	G.f &= ~G_SCRIPT_AUTOEXEC;
-	else												G.f |=  G_SCRIPT_AUTOEXEC;
+	if ((G.f & G_SCRIPT_OVERRIDE_PREF) == 0) {
+		/* Blender run with --enable-autoexec */
+		UserDef *userdef = (UserDef*)ptr->data;
+		if (userdef->flag & USER_SCRIPT_AUTOEXEC_DISABLE)       G.f &= ~G_SCRIPT_AUTOEXEC;
+		else                                                                                            G.f |=  G_SCRIPT_AUTOEXEC;
+	}
+}
+
+static int rna_userdef_script_autoexec_editable(Main *bmain, Scene *scene, PointerRNA *ptr) {
+	/* Disable "Auto Run Python Scripts" checkbox unless Blender run with --enable-autoexec */
+	return !(G.f & G_SCRIPT_OVERRIDE_PREF);
 }
 
 static void rna_userdef_mipmap_update(Main *bmain, Scene *scene, PointerRNA *ptr)
@@ -2729,6 +2737,8 @@ static void rna_def_userdef_system(Blend
 	                         "Allow any .blend file to run scripts automatically "
 	                         "(unsafe with blend files from an untrusted source)");
 	RNA_def_property_update(prop, 0, "rna_userdef_script_autoexec_update");
+	/* Disable "Auto Run Python Scripts" checkbox unless Blender run with --enable-autoexec */
+	RNA_def_property_editable_func(prop, "rna_userdef_script_autoexec_editable");
 
 	prop= RNA_def_property(srna, "use_tabs_as_spaces", PROP_BOOLEAN, PROP_NONE);
 	RNA_def_property_boolean_negative_sdna(prop, NULL, "flag", USER_TXT_TABSTOSPACES_DISABLE);
diff -Npur blender-2.61.orig/source/blender/windowmanager/intern/wm_files.c blender-2.61/source/blender/windowmanager/intern/wm_files.c
--- blender-2.61.orig/source/blender/windowmanager/intern/wm_files.c	2011-12-20 20:47:10.943735949 +0100
+++ blender-2.61/source/blender/windowmanager/intern/wm_files.c	2011-12-20 20:52:16.097730555 +0100
@@ -286,13 +286,18 @@ static void wm_init_userdef(bContext *C)
 
 	/* set the python auto-execute setting from user prefs */
 	/* enabled by default, unless explicitly enabled in the command line which overrides */
-	if((G.f & G_SCRIPT_OVERRIDE_PREF) == 0) {
+	if (! G.background && ((G.f & G_SCRIPT_OVERRIDE_PREF) == 0)) {
+		/* Blender run with --enable-autoexec */
 		if ((U.flag & USER_SCRIPT_AUTOEXEC_DISABLE) == 0) G.f |=  G_SCRIPT_AUTOEXEC;
 		else											  G.f &= ~G_SCRIPT_AUTOEXEC;
 	}
 
 	/* update tempdir from user preferences */
 	BLI_init_temporary_dir(U.tempdir);
+
+	/* Workaround to fix default of "Auto Run Python Scripts" checkbox */
+	if ((G.f & G_SCRIPT_OVERRIDE_PREF) && !(G.f & G_SCRIPT_AUTOEXEC))
+		U.flag |= USER_SCRIPT_AUTOEXEC_DISABLE;
 }
 
 
diff -Npur blender-2.61.orig/source/blender/windowmanager/intern/wm_operators.c blender-2.61/source/blender/windowmanager/intern/wm_operators.c
--- blender-2.61.orig/source/blender/windowmanager/intern/wm_operators.c	2011-12-20 20:47:10.943735949 +0100
+++ blender-2.61/source/blender/windowmanager/intern/wm_operators.c	2011-12-20 20:57:09.176725378 +0100
@@ -1601,12 +1601,13 @@ static int wm_open_mainfile_exec(bContex
 		G.fileflags &= ~G_FILE_NO_UI;
 	else
 		G.fileflags |= G_FILE_NO_UI;
-		
-	if(RNA_boolean_get(op->ptr, "use_scripts"))
+
+	/* Restrict "Trusted Source" mode to Blender in --enable-autoexec mode */
+	if(RNA_boolean_get(op->ptr, "use_scripts") && (!(G.f & G_SCRIPT_OVERRIDE_PREF)))
 		G.f |= G_SCRIPT_AUTOEXEC;
 	else
 		G.f &= ~G_SCRIPT_AUTOEXEC;
-	
+
 	// XXX wm in context is not set correctly after WM_read_file -> crash
 	// do it before for now, but is this correct with multiple windows?
 	WM_event_add_notifier(C, NC_WINDOW, NULL);
@@ -1618,6 +1619,8 @@ static int wm_open_mainfile_exec(bContex
 
 static void WM_OT_open_mainfile(wmOperatorType *ot)
 {
+	PropertyRNA * use_scripts_checkbox = NULL;
+
 	ot->name= "Open Blender File";
 	ot->idname= "WM_OT_open_mainfile";
 	ot->description="Open a Blender file";
@@ -1629,7 +1632,12 @@ static void WM_OT_open_mainfile(wmOperat
 	WM_operator_properties_filesel(ot, FOLDERFILE|BLENDERFILE, FILE_BLENDER, FILE_OPENFILE, WM_FILESEL_FILEPATH);
 
 	RNA_def_boolean(ot->srna, "load_ui", 1, "Load UI", "Load user interface setup in the .blend file");
-	RNA_def_boolean(ot->srna, "use_scripts", 1, "Trusted Source", "Allow blend file execute scripts automatically, default available from system preferences");
+	use_scripts_checkbox = RNA_def_boolean(ot->srna, "use_scripts",
+			!!(G.f & G_SCRIPT_AUTOEXEC), "Trusted Source",
+	                "Allow blend file execute scripts automatically, default available from system preferences");
+	/* Disable "Trusted Source" checkbox unless Blender run with --enable-autoexec */
+	if (use_scripts_checkbox && (G.f & G_SCRIPT_OVERRIDE_PREF))
+	        RNA_def_property_clear_flag(use_scripts_checkbox, PROP_EDITABLE);
 }
 
 /* **************** link/append *************** */
diff -Npur blender-2.61.orig/source/creator/creator.c blender-2.61/source/creator/creator.c
--- blender-2.61.orig/source/creator/creator.c	2011-12-20 20:47:10.878735951 +0100
+++ blender-2.61/source/creator/creator.c	2011-12-20 20:59:23.778723050 +0100
@@ -262,6 +262,7 @@ static int print_help(int UNUSED(argc),
 
 	printf("\n");
 
+	BLI_argsPrintArgDoc(ba, "-666");
 	BLI_argsPrintArgDoc(ba, "--enable-autoexec");
 	BLI_argsPrintArgDoc(ba, "--disable-autoexec");
 
@@ -330,14 +331,14 @@ static int end_arguments(int UNUSED(argc
 static int enable_python(int UNUSED(argc), const char **UNUSED(argv), void *UNUSED(data))
 {
 	G.f |= G_SCRIPT_AUTOEXEC;
-	G.f |= G_SCRIPT_OVERRIDE_PREF;
+	G.f &= ~G_SCRIPT_OVERRIDE_PREF;  /* Enables turning G_SCRIPT_AUTOEXEC off from user prefs */
 	return 0;
 }
 
 static int disable_python(int UNUSED(argc), const char **UNUSED(argv), void *UNUSED(data))
 {
 	G.f &= ~G_SCRIPT_AUTOEXEC;
-	G.f |= G_SCRIPT_OVERRIDE_PREF;
+	G.f |= G_SCRIPT_OVERRIDE_PREF;  /* Disables turning G_SCRIPT_AUTOEXEC on from user prefs */
 	return 0;
 }
 
@@ -1042,6 +1043,7 @@ static void setupArguments(bContext *C,
 #  define 	PY_DISABLE_AUTO ", (compiled as non-standard default)"
 #endif
 
+	BLI_argsAdd(ba, 1, NULL, "-666", "\n\tEnable automatic python script execution (port from CVE-2009-3850 patch to Blender 2.61)" PY_ENABLE_AUTO, enable_python, NULL);
 	BLI_argsAdd(ba, 1, "-y", "--enable-autoexec", "\n\tEnable automatic python script execution" PY_ENABLE_AUTO, enable_python, NULL);
 	BLI_argsAdd(ba, 1, "-Y", "--disable-autoexec", "\n\tDisable automatic python script execution (pydrivers, pyconstraints, pynodes)" PY_DISABLE_AUTO, disable_python, NULL);