Prevent access to .template_object when in security mode to prevent PHP code injection vulnerability

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- Prevent access to `$smarty.template_object` in Security mode
+
 ## [3.1.38] - 2021-01-08
 
 ### Fixed

libs/sysplugins/smarty_internal_compile_private_special_variable.php

@@ -81,6 +81,10 @@ class Smarty_Internal_Compile_Private_Special_Variable extends Smarty_Internal_C
                 case 'template':
                     return 'basename($_smarty_tpl->source->filepath)';
                 case 'template_object':
+                    if (isset($compiler->smarty->security_policy)) {
+                        $compiler->trigger_template_error("(secure mode) template_object not permitted");
+                        break;
+                    }
                     return '$_smarty_tpl';
                 case 'current_dir':
                     return 'dirname($_smarty_tpl->source->filepath)';