From 151b13a424b8e6ff8f4da58ed43b8d1602734c69 Mon Sep 17 00:00:00 2001
From: Mike Welsh <mwelsh@gmail.com>
Date: Thu, 3 Sep 2020 17:29:32 -0700
Subject: [PATCH] avm1: ExternalInterface properties are read only

---
 core/src/avm1/globals/external_interface.rs | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/core/src/avm1/globals/external_interface.rs b/core/src/avm1/globals/external_interface.rs
index f4fff8cde..6626cca98 100644
--- a/core/src/avm1/globals/external_interface.rs
+++ b/core/src/avm1/globals/external_interface.rs
@@ -81,14 +81,14 @@ pub fn create_external_interface_object<'gc>(
             fn_proto,
         ),
         None,
-        Attribute::DontDelete | Attribute::DontEnum,
+        Attribute::DontDelete | Attribute::DontEnum | Attribute::ReadOnly,
     );
 
     object.force_set_function(
         "addCallback",
         add_callback,
         gc_context,
-        Attribute::DontDelete | Attribute::DontEnum,
+        Attribute::DontDelete | Attribute::DontEnum | Attribute::ReadOnly,
         Some(fn_proto),
     );
 
@@ -96,7 +96,7 @@ pub fn create_external_interface_object<'gc>(
         "call",
         call,
         gc_context,
-        Attribute::DontDelete | Attribute::DontEnum,
+        Attribute::DontDelete | Attribute::DontEnum | Attribute::ReadOnly,
         Some(fn_proto),
     );