[patch] Proposed patch for CVE-2009-3850 against Blender 2.57 (v2)

blender-2.57-CVE-2009-3850-v2.patch (text/plain), 8.24 KB, created by Sebastian Pipping on 2011-05-17 15:44:18 UTC

From c4181c5639da5c6a6df31b434498a44d0d680487 Mon Sep 17 00:00:00 2001
From: Sebastian Pipping <[e-mail]>
Date: Tue, 17 May 2011 17:37:11 +0200
Subject: [PATCH] Disable execution of embedded Python code unless run with
 --enable-autoexec|-y|-666  (CVE-2009-3850)

---
 source/blender/blenkernel/intern/blender.c         |    3 ++-
 source/blender/makesrna/intern/rna_userdef.c       |   16 +++++++++++++---
 source/blender/windowmanager/intern/wm_files.c     |    7 ++++++-
 source/blender/windowmanager/intern/wm_operators.c |   16 ++++++++++++----
 source/creator/creator.c                           |   10 ++++++----
 5 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/source/blender/blenkernel/intern/blender.c b/source/blender/blenkernel/intern/blender.c
index 5f08505..9c27ac7 100644
--- a/source/blender/blenkernel/intern/blender.c
+++ b/source/blender/blenkernel/intern/blender.c
@@ -141,7 +141,8 @@ void initglobals(void)
 	G.charmin = 0x0000;
 	G.charmax = 0xffff;
 	
-	G.f |= G_SCRIPT_AUTOEXEC;
+	G.f &= ~G_SCRIPT_AUTOEXEC;
+	G.f |= G_SCRIPT_OVERRIDE_PREF;  /* Disables turning G_SCRIPT_AUTOEXEC on from user prefs */
 }
 
 /***/
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index e9a9ddc..218b50a 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -99,9 +99,17 @@ static void rna_userdef_show_manipulator_update(Main *bmain, Scene *scene, Point
 
 static void rna_userdef_script_autoexec_update(Main *bmain, Scene *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)
@@ -2505,6 +2513,8 @@ static void rna_def_userdef_system(BlenderRNA *brna)
 	RNA_def_property_boolean_negative_sdna(prop, NULL, "flag", USER_SCRIPT_AUTOEXEC_DISABLE);
 	RNA_def_property_ui_text(prop, "Auto Run Python Scripts", "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 --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index f4f7af0..37a9664 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -270,11 +270,16 @@ 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;
 	}
 	if(U.tempdir[0]) BLI_where_is_temp(btempdir, FILE_MAX, 1);
+
+	/* 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;
 }
 
 void WM_read_file(bContext *C, const char *name, ReportList *reports)
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 28df023..a2142a5 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -1471,12 +1471,13 @@ static int wm_open_mainfile_exec(bContext *C, wmOperator *op)
 		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);
@@ -1488,6 +1489,8 @@ static int wm_open_mainfile_exec(bContext *C, wmOperator *op)
 
 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";
@@ -1499,7 +1502,12 @@ static void WM_OT_open_mainfile(wmOperatorType *ot)
 	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 --git a/source/creator/creator.c b/source/creator/creator.c
index c687cc2..1da282f 100644
--- a/source/creator/creator.c
+++ b/source/creator/creator.c
@@ -278,6 +278,7 @@ static int print_help(int UNUSED(argc), const char **UNUSED(argv), void *data)
 
 	printf("\n");
 
+	BLI_argsPrintArgDoc(ba, "-666");
 	BLI_argsPrintArgDoc(ba, "--enable-autoexec");
 	BLI_argsPrintArgDoc(ba, "--disable-autoexec");
 
@@ -359,14 +360,14 @@ static int end_arguments(int UNUSED(argc), const char **UNUSED(argv), void *UNUS
 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;
 }
 
@@ -1075,8 +1076,9 @@ static void setupArguments(bContext *C, bArgs *ba, SYS_SystemHandle *syshandle)
 
 	BLI_argsAdd(ba, 1, "-v", "--version", "\n\tPrint Blender version and exit", print_version, NULL);
 
-	BLI_argsAdd(ba, 1, "-y", "--enable-autoexec", "\n\tEnable automatic python script execution (default)", enable_python, NULL);
-	BLI_argsAdd(ba, 1, "-Y", "--disable-autoexec", "\n\tDisable automatic python script execution (pydrivers, pyconstraints, pynodes)", disable_python, NULL);
+	BLI_argsAdd(ba, 1, NULL, "-666", "\n\tEnable automatic python script execution (port from CVE-2009-3850 patch to Blender 2.49b)", enable_python, NULL);
+	BLI_argsAdd(ba, 1, "-y", "--enable-autoexec", "\n\tEnable automatic python script execution", enable_python, NULL);
+	BLI_argsAdd(ba, 1, "-Y", "--disable-autoexec", "\n\tDisable automatic python script execution (pydrivers, pyconstraints, pynodes) (default)", disable_python, NULL);
 
 	BLI_argsAdd(ba, 1, "-b", "--background", "<file>\n\tLoad <file> in background (often used for UI-less rendering)", background_mode, NULL);
 
-- 
1.7.5.rc3