Changelog

Fixes #702.

CHANGELOG.md

@@ -6,6 +6,38 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Fixed
+- Fixed illegal characters bug in math function security check [#702](https://github.com/smarty-php/smarty/issues/702)
+
+## [3.1.43] - 2022-01-10
+
+### Security
+- Prevent evasion of the `static_classes` security policy. This addresses CVE-2021-21408
+
+## [3.1.42] - 2022-01-10
+
+### Security
+- Prevent arbitrary PHP code execution through maliciously crafted expression for the math function. This addresses CVE-2021-29454
+
+## [3.1.41] - 2022-01-09
+
+### Security
+- Rewrote the mailto function to not use `eval` when encoding with javascript
+
+## [3.1.40] - 2021-10-13
+
+### Changed
+- modifier escape now triggers a E_USER_NOTICE when an unsupported escape type is used https://github.com/smarty-php/smarty/pull/649
+
+### Security
+- More advanced javascript escaping to handle https://html.spec.whatwg.org/multipage/scripting.html#restrictions-for-contents-of-script-elements thanks to m-haritonov
+
+## [3.1.39] - 2021-02-17
+
+### Security
+- Prevent access to `$smarty.template_object` in sandbox mode. This addresses CVE-2021-26119.
+- Fixed code injection vulnerability by using illegal function names in `{function name='blah'}{/function}`. This addresses CVE-2021-26120.
+
 ## [3.1.38] - 2021-01-08
 
 ### Fixed

README.md

@@ -18,7 +18,7 @@ Smarty can be run with PHP 5.2 to PHP 7.4.
 
 > Read the NEW_FEATURES and INHERITANCE_RELEASE_NOTES file for recent extensions to Smarty 3.1 functionality
 
-Smarty versions 3.1.11 or later are now on github and can be installed with Composer.
+Smarty versions 3.1.11 or later are now on GitHub and can be installed with Composer.
 
 
 The "smarty/smarty" package will start at libs/....   subfolder.

SECURITY.md

@@ -0,0 +1,19 @@
+# Security Policy
+
+## Supported Versions
+
+Smarty currently supports the latest minor version of Smarty 3 and Smarty 4. (Smarty 4 has not been released yet.)
+
+| Version | Supported          |
+| ------- | ------------------ |
+| 4.0.x   | :white_check_mark: |
+| 3.1.x   | :white_check_mark: |
+| < 3.1   | :x:                |
+
+## Reporting a Vulnerability
+
+ If you have discovered a security issue with Smarty, please contact us at mail [at] simonwisselink.nl. Do not 
+ disclose your findings publicly and PLEASE PLEASE do not file an Issue.
+ 
+We will try to confirm the vulnerability and develop a fix if appropriate. When we release the fix, we will publish 
+a security release. Please let us know if you want to be credited.

lexer/smarty_internal_templateparser.y

@@ -758,6 +758,9 @@ value(res)       ::= doublequoted_with_quotes(s). {
 
 
 value(res)    ::= varindexed(vi) DOUBLECOLON static_class_access(r). {
+    if ($this->security && $this->security->static_classes !== array()) {
+        $this->compiler->trigger_template_error('dynamic static class not allowed by security setting');
+    }
     $prefixVar = $this->compiler->getNewPrefixVariable();
     if (vi['var'] === '\'smarty\'') {
         $this->compiler->appendPrefixCode("<?php {$prefixVar} = ". $this->compiler->compileTag('private_special_variable',array(),vi['smarty_internal_index']).';?>');

libs/Smarty.class.php

@@ -111,7 +111,7 @@ class Smarty extends Smarty_Internal_TemplateBase
     /**
      * smarty version
      */
-    const SMARTY_VERSION = '3.1.38';
+    const SMARTY_VERSION = '3.1.43';
     /**
      * define variable scopes
      */

libs/plugins/function.mailto.php

@@ -94,22 +94,19 @@ function smarty_function_mailto($params)
         );
         return;
     }
-    // FIXME: (rodneyrehm) document.write() excues me what? 1998 has passed!
     if ($encode === 'javascript') {
-        $string = 'document.write(\'<a href="mailto:' . $address . '" ' . $extra . '>' . $text . '</a>\');';
+	    $string = '<a href="mailto:' . $address . '" ' . $extra . '>' . $text . '</a>';
         $js_encode = '';
         for ($x = 0, $_length = strlen($string); $x < $_length; $x++) {
             $js_encode .= '%' . bin2hex($string[ $x ]);
         }
-        return '<script type="text/javascript">eval(unescape(\'' . $js_encode . '\'))</script>';
+        return '<script type="text/javascript">document.write(unescape(\'' . $js_encode . '\'))</script>';
     } elseif ($encode === 'javascript_charcode') {
         $string = '<a href="mailto:' . $address . '" ' . $extra . '>' . $text . '</a>';
-        for ($x = 0, $y = strlen($string); $x < $y; $x++) {
+        for ($x = 0, $_length = strlen($string); $x < $_length; $x++) {
             $ord[] = ord($string[ $x ]);
         }
-        $_ret = "<script type=\"text/javascript\" language=\"javascript\">\n" . "{document.write(String.fromCharCode(" .
+	    return '<script type="text/javascript">document.write(String.fromCharCode(' . implode(',', $ord) . '))</script>';
-                implode(',', $ord) . "))" . "}\n" . "</script>\n";
-        return $_ret;
     } elseif ($encode === 'hex') {
         preg_match('!^(.*)(\?.*)$!', $address, $match);
         if (!empty($match[ 2 ])) {

libs/plugins/function.math.php

@@ -28,7 +28,12 @@ function smarty_function_math($params, $template)
             'int'   => true,
             'abs'   => true,
             'ceil'  => true,
+            'acos'   => true,
+            'acosh'   => true,
             'cos'   => true,
+            'cosh'   => true,
+            'deg2rad'   => true,
+            'rad2deg'   => true,
             'exp'   => true,
             'floor' => true,
             'log'   => true,
@@ -39,27 +44,51 @@ function smarty_function_math($params, $template)
             'pow'   => true,
             'rand'  => true,
             'round' => true,
+            'asin'   => true,
+            'asinh'   => true,
             'sin'   => true,
+            'sinh'   => true,
             'sqrt'  => true,
             'srand' => true,
-            'tan'   => true
+            'atan'   => true,
+            'atanh'   => true,
+            'tan'   => true,
+            'tanh'   => true
         );
+
     // be sure equation parameter is present
     if (empty($params[ 'equation' ])) {
         trigger_error("math: missing equation parameter", E_USER_WARNING);
         return;
     }
     $equation = $params[ 'equation' ];
+
+    // Remove whitespaces
+    $equation = preg_replace('/\s+/', '', $equation);
+
+    // Adapted from https://www.php.net/manual/en/function.eval.php#107377
+    $number = '(?:\d+(?:[,.]\d+)?|pi|π)'; // What is a number
+    $functionsOrVars = '((?:0x[a-fA-F0-9]+)|([a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*))';
+    $operators = '[+\/*\^%-]'; // Allowed math operators
+    $regexp = '/^(('.$number.'|'.$functionsOrVars.'|('.$functionsOrVars.'\s*\((?1)+\)|\((?1)+\)))(?:'.$operators.'(?1))?)+$/';
+
+    if (!preg_match($regexp, $equation)) {
+        trigger_error("math: illegal characters", E_USER_WARNING);
+        return;
+    }
+
     // make sure parenthesis are balanced
     if (substr_count($equation, '(') !== substr_count($equation, ')')) {
         trigger_error("math: unbalanced parenthesis", E_USER_WARNING);
         return;
     }
+
     // disallow backticks
     if (strpos($equation, '`') !== false) {
         trigger_error("math: backtick character not allowed in equation", E_USER_WARNING);
         return;
     }
+
     // also disallow dollar signs
     if (strpos($equation, '$') !== false) {
         trigger_error("math: dollar signs not allowed in equation", E_USER_WARNING);
@@ -96,6 +125,7 @@ function smarty_function_math($params, $template)
     }
     $smarty_math_result = null;
     eval("\$smarty_math_result = " . $equation . ";");
+
     if (empty($params[ 'format' ])) {
         if (empty($params[ 'assign' ])) {
             return $smarty_math_result;

libs/plugins/modifier.escape.php

@@ -184,7 +184,11 @@ function smarty_modifier_escape($string, $esc_type = 'html', $char_set = null, $
                     '"'  => '\\"',
                     "\r" => '\\r',
                     "\n" => '\\n',
-                    '</' => '<\/'
+                    '</' => '<\/',
+                    // see https://html.spec.whatwg.org/multipage/scripting.html#restrictions-for-contents-of-script-elements
+                    '<!--' => '<\!--',
+                    '<s'   => '<\s',
+                    '<S'   => '<\S'
                 )
             );
         case 'mail':
@@ -250,6 +254,7 @@ function smarty_modifier_escape($string, $esc_type = 'html', $char_set = null, $
             }
             return $return;
         default:
+            trigger_error("escape: unsupported type: $esc_type - returning unmodified string", E_USER_NOTICE);
             return $string;
     }
 }

libs/plugins/modifiercompiler.escape.php

@@ -89,9 +89,10 @@ function smarty_modifiercompiler_escape($params, Smarty_Internal_TemplateCompile
                 return 'preg_replace("%(?<!\\\\\\\\)\'%", "\\\'",' . $params[ 0 ] . ')';
             case 'javascript':
                 // escape quotes and backslashes, newlines, etc.
+                // see https://html.spec.whatwg.org/multipage/scripting.html#restrictions-for-contents-of-script-elements
                 return 'strtr(' .
                        $params[ 0 ] .
-                       ', array("\\\\" => "\\\\\\\\", "\'" => "\\\\\'", "\"" => "\\\\\"", "\\r" => "\\\\r", "\\n" => "\\\n", "</" => "<\/" ))';
+                       ', array("\\\\" => "\\\\\\\\", "\'" => "\\\\\'", "\"" => "\\\\\"", "\\r" => "\\\\r", "\\n" => "\\\n", "</" => "<\/", "<!--" => "<\!--", "<s" => "<\s", "<S" => "<\S" ))';
         }
     } catch (SmartyException $e) {
         // pass through to regular plugin fallback

libs/sysplugins/smarty_internal_compile_function.php

@@ -58,6 +58,11 @@ class Smarty_Internal_Compile_Function extends Smarty_Internal_CompileBase
         }
         unset($_attr[ 'nocache' ]);
         $_name = trim($_attr[ 'name' ], '\'"');
+
+        if (!preg_match('/^[a-zA-Z0-9_\x80-\xff]+$/', $_name)) {
+	        $compiler->trigger_template_error("Function name contains invalid characters: {$_name}", null, true);
+        }
+
         $compiler->parent_compiler->tpl_function[ $_name ] = array();
         $save = array(
             $_attr, $compiler->parser->current_buffer, $compiler->template->compiled->has_nocache_code,

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)';

libs/sysplugins/smarty_internal_templateparser.php

@@ -2837,6 +2837,10 @@ class Smarty_Internal_Templateparser
     // line 765 "../smarty/lexer/smarty_internal_templateparser.y"
     public function yy_r95()
     {
+        if ($this->security && $this->security->static_classes !== array()) {
+            $this->compiler->trigger_template_error('dynamic static class not allowed by security setting');
+        }
+
         $prefixVar = $this->compiler->getNewPrefixVariable();
         if ($this->yystack[ $this->yyidx + -2 ]->minor[ 'var' ] === '\'smarty\'') {
             $this->compiler->appendPrefixCode("<?php {$prefixVar} = " .

make-release.sh

@@ -1,6 +1,11 @@
 #!/bin/bash
 
-printf 'Creating release %s\n' "$1"
+if [[ "$1" =~ ^3\.[0-9\.-rc]+$ ]]; then
+   printf 'Creating release %s\n' "$1"
+else
+   echo "Invalid version number: $1. This script can only make v3.x.x releases."
+   exit 1;
+fi
 
 git checkout -b "release/$1"
 sed -i "s/## \\[Unreleased\\]/## \\[Unreleased\\]\\n\\n## \\[$1\\] - $(date +%Y-%m-%d)/" CHANGELOG.md
@@ -9,11 +14,13 @@ sed -i "s/const SMARTY_VERSION = '[^']\+';/const SMARTY_VERSION = '$1';/" libs/S
 git add CHANGELOG.md libs/Smarty.class.php
 git commit -m "version bump"
 
-git checkout master
+git checkout support/3.1
 git pull
 git merge --no-ff "release/$1"
 git branch -d "release/$1"
 git tag -a "v$1" -m "Release $1"
-git push --follow-tags
 
 printf 'Done creating release %s\n' "$1"
+
+# shellcheck disable=SC2016
+printf 'Run `git push --follow-tags origin` to publish it.\n'

tests/UnitTests/SecurityTests/SecurityTest.php

@@ -298,18 +298,38 @@ class SecurityTest extends PHPUnit_Smarty
         $this->assertEquals('25', $this->smarty->fetch($tpl));
     }
 
-/**
+	/**
- * test not trusted PHP function
+	 * test not trusted PHP function
-  * @expectedException        SmartyException
+	 * @expectedException        SmartyException
-  * @expectedExceptionMessage   access to static class 'mysecuritystaticclass' not allowed by security setting
+	 * @expectedExceptionMessage   access to static class 'mysecuritystaticclass' not allowed by security setting
-  * @runInSeparateProcess
+	 */
-  * @preserveGlobalState disabled
+	public function testNotTrustedStaticClass()
-  */
+	{
-    public function testNotTrustedStaticClass()
+		$this->smarty->security_policy->static_classes = array('null');
-    {
+		$this->smarty->fetch('string:{mysecuritystaticclass::square(5)}');
-        $this->smarty->security_policy->static_classes = array('null');
+	}
-            $this->smarty->fetch('string:{mysecuritystaticclass::square(5)}');
+
-    }
+	/**
+	 * test not trusted PHP function
+	 * @expectedException        SmartyException
+	 * @expectedExceptionMessage   dynamic static class not allowed by security setting
+	 */
+	public function testNotTrustedStaticClassEval()
+	{
+		$this->smarty->security_policy->static_classes = array('null');
+		$this->smarty->fetch('string:{$test = "mysecuritystaticclass"}{$test::square(5)}');
+	}
+
+	/**
+	 * test not trusted PHP function
+	 * @expectedException        SmartyException
+	 * @expectedExceptionMessage   dynamic static class not allowed by security setting
+	 */
+	public function testNotTrustedStaticClassSmartyVar()
+	{
+		$this->smarty->security_policy->static_classes = array('null');
+		$this->smarty->fetch('string:{$smarty.template_object::square(5)}');
+	}
 
     public function testChangedTrustedDirectory()
     {
@@ -382,6 +402,15 @@ class SecurityTest extends PHPUnit_Smarty
         $this->smarty->security_policy->trusted_uri = array();
         $this->assertContains('<title>Preface | Smarty</title>', $this->smarty->fetch('string:{fetch file="https://www.smarty.net/docs/en/preface.tpl"}'));
     }
+
+    /**
+     * In security mode, accessing $smarty.template_object should be illegal.
+     * @expectedException SmartyCompilerException
+     */
+    public function testSmartyTemplateObject() {
+        $this->smarty->display('string:{$smarty.template_object}');
+    }
+
 }
 
 class mysecuritystaticclass

tests/UnitTests/TemplateSource/TagTests/PluginFunction/PluginFunctionMailtoTest.php

@@ -54,7 +54,7 @@ class PluginFunctionMailtoTest extends PHPUnit_Smarty
 
     public function testEncodeJavascript()
     {
-        $result = '<script type="text/javascript">eval(unescape(\'%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%22%20%3e%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%3c%2f%61%3e%27%29%3b\'))</script>';
+        $result = '<script type="text/javascript">document.write(unescape(\'%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%22%20%3e%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%3c%2f%61%3e\'))</script>';
         $tpl = $this->smarty->createTemplate('eval:{mailto address="me@example.com" encode="javascript"}');
         $this->assertEquals(str_replace("\r", '', $result), $this->smarty->fetch($tpl));
     }
@@ -62,7 +62,7 @@ class PluginFunctionMailtoTest extends PHPUnit_Smarty
     public function testEncodeJavascriptWithoutMbstring()
     {
         Smarty::$_MBSTRING = false;
-        $result = '<script type="text/javascript">eval(unescape(\'%64%6f%63%75%6d%65%6e%74%2e%77%72%69%74%65%28%27%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%22%20%3e%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%3c%2f%61%3e%27%29%3b\'))</script>';
+        $result = '<script type="text/javascript">document.write(unescape(\'%3c%61%20%68%72%65%66%3d%22%6d%61%69%6c%74%6f%3a%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%22%20%3e%6d%65%40%65%78%61%6d%70%6c%65%2e%63%6f%6d%3c%2f%61%3e\'))</script>';
         $tpl = $this->smarty->createTemplate('eval:{mailto address="me@example.com" encode="javascript"}');
         $this->assertEquals(str_replace("\r", '', $result), $this->smarty->fetch($tpl));
         Smarty::$_MBSTRING = true;
@@ -70,7 +70,7 @@ class PluginFunctionMailtoTest extends PHPUnit_Smarty
 
     public function testEncodeJavascriptCharcode()
     {
-        $result = "<script type=\"text/javascript\" language=\"javascript\">\n{document.write(String.fromCharCode(60,97,32,104,114,101,102,61,34,109,97,105,108,116,111,58,109,101,64,101,120,97,109,112,108,101,46,99,111,109,34,32,62,109,101,64,101,120,97,109,112,108,101,46,99,111,109,60,47,97,62))}\n</script>\n";
+        $result = '<script type="text/javascript">document.write(String.fromCharCode(60,97,32,104,114,101,102,61,34,109,97,105,108,116,111,58,109,101,64,101,120,97,109,112,108,101,46,99,111,109,34,32,62,109,101,64,101,120,97,109,112,108,101,46,99,111,109,60,47,97,62))</script>';
         $tpl = $this->smarty->createTemplate('eval:{mailto address="me@example.com" encode="javascript_charcode"}');
         $this->assertEquals(str_replace("\r", '', $result), $this->smarty->fetch($tpl));
     }
@@ -78,7 +78,7 @@ class PluginFunctionMailtoTest extends PHPUnit_Smarty
     public function testEncodeJavascriptCharcodeWithoutMbstring()
     {
         Smarty::$_MBSTRING = false;
-        $result = "<script type=\"text/javascript\" language=\"javascript\">\n{document.write(String.fromCharCode(60,97,32,104,114,101,102,61,34,109,97,105,108,116,111,58,109,101,64,101,120,97,109,112,108,101,46,99,111,109,34,32,62,109,101,64,101,120,97,109,112,108,101,46,99,111,109,60,47,97,62))}\n</script>\n";
+        $result = '<script type="text/javascript">document.write(String.fromCharCode(60,97,32,104,114,101,102,61,34,109,97,105,108,116,111,58,109,101,64,101,120,97,109,112,108,101,46,99,111,109,34,32,62,109,101,64,101,120,97,109,112,108,101,46,99,111,109,60,47,97,62))</script>';
         $tpl = $this->smarty->createTemplate('eval:{mailto address="me@example.com" encode="javascript_charcode"}');
         $this->assertEquals(str_replace("\r", '', $result), $this->smarty->fetch($tpl));
         Smarty::$_MBSTRING = true;

tests/UnitTests/TemplateSource/TagTests/TemplateFunction/CompileFunctionTest.php

@@ -431,5 +431,14 @@ class CompileFunctionTest extends PHPUnit_Smarty
                      array("{function name=simple}A{\$foo}\nC{/function}{call name='simple'}", "Abar\nC", 'T14', $i++),
                      array("{function name=simple}A\n{\$foo}\nC{/function}{call name='simple'}", "A\nbar\nC", 'T15', $i++),
         );
-            }
+    }
+
+    /**
+     * Test handling of function names that are a security risk
+     * @expectedException        SmartyCompilerException
+     */
+    public function testIllegalFunctionName() {
+	    $this->smarty->fetch('string:{function name=\'rce(){};echo "hi";function \'}{/function}');
+    }
+
 }

tests/UnitTests/TemplateSource/ValueTests/Math/MathTest.php

@@ -44,6 +44,14 @@ class MathTest extends PHPUnit_Smarty
         $this->assertEquals($expected, $this->smarty->fetch($tpl));
     }
 
+    public function testMultipleOperators()
+    {
+        $this->smarty->disableSecurity();
+        $expected = "2 -- 2";
+        $tpl = $this->smarty->createTemplate('eval:{$x = 5}{$y = 4}{math equation="x - y + 1" x=$x y=$y} -- {math equation="5 - 4 + 1"}');
+        $this->assertEquals($expected, $this->smarty->fetch($tpl));
+    }
+
     public function testSyntaxSin()
     {
         $this->smarty->disableSecurity();
@@ -107,4 +115,35 @@ class MathTest extends PHPUnit_Smarty
         $tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="x * y" x=$x y=$y format="%0.2f"} -- {math equation="20.5 / 5" format="%0.2f"}');
         $this->assertEquals($expected, $this->smarty->fetch($tpl));
     }
+
+	/**
+	 * @expectedException PHPUnit_Framework_Error_Warning
+	 */
+	public function testBackticksIllegal()
+	{
+		$expected = "22.00";
+		$tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="`ls` x * y" x=$x y=$y}');
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
+	/**
+	 * @expectedException PHPUnit_Framework_Error_Warning
+	 */
+	public function testDollarSignsIllegal()
+	{
+		$expected = "22.00";
+		$tpl = $this->smarty->createTemplate('eval:{$x = "4"}{$y = "5.5"}{math equation="$" x=$x y=$y}');
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
+	/**
+	 * @expectedException PHPUnit_Framework_Error_Warning
+	 */
+	public function testBracketsIllegal()
+	{
+		$expected = "I";
+		$tpl = $this->smarty->createTemplate('eval:{$x = "0"}{$y = "1"}{math equation="((y/x).(x))[x]" x=$x y=$y}');
+		$this->assertEquals($expected, $this->smarty->fetch($tpl));
+	}
+
 }