feat: implement safe title processing in MainContent, MainContentTabbed, and MainContentTabless

- Introduced a new function `processTitle` to safely handle page titles by replacing PHP variables with their values without using eval.
- Updated title handling in MainContent, MainContentTabbed, and MainContentTabless to utilize the new `processTitle` function, enhancing security and maintainability.

emhttp/plugins/dynamix/include/DefaultPageLayout/MainContent.php

@@ -13,6 +13,27 @@ $tabbed = $display['tabs'] == 0 && count($pages) > 1;
 $contentInclude = $tabbed ? 'MainContentTabbed.php' : 'MainContentTabless.php';
 
 $defaultIcon = "<i class=\"icon-app PanelIcon\"></i>";
+
+/**
+ * Safely processes page titles by replacing PHP variables with their values
+ * 
+ * @param string $rawTitle The unprocessed title that may contain variable references
+ * @return string Processed title with variables substituted
+ */
+function processTitle($rawTitle) {
+    // Safely replace any variables in the title without eval
+    $title = htmlspecialchars((string)$rawTitle);
+    return preg_replace_callback(
+        '/\$([a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*)/',
+        function($matches) {
+            return isset($GLOBALS[$matches[1]]) ? 
+                   htmlspecialchars((string)$GLOBALS[$matches[1]]) : 
+                   '$'.$matches[1];
+        },
+        $title
+    );
+}
+
 function process_icon($icon, $docroot, $root) {
     global $defaultIcon;
     if (substr($icon, -4) == '.png') {
@@ -44,8 +65,8 @@ function process_icon($icon, $docroot, $root) {
  * @return string HTML for the Panel element
  */
 function generatePanel($pg, $path, $defaultIcon, $docroot, $useTabCookie = false) {
-    $panelTitle = ''; // to appease the linter because eval is used below
-    eval("\$panelTitle=\"".htmlspecialchars((string)$pg['Title'])."\";"); // ensures variables in any .page title are used
+    // Process title using our safe variable substitution function
+    $panelTitle = processTitle($pg['Title']);
     $icon = _var($pg, 'Icon', $defaultIcon);
     $icon = process_icon($icon, $docroot, $pg['root']);
 

emhttp/plugins/dynamix/include/DefaultPageLayout/MainContentTabbed.php

@@ -10,10 +10,7 @@
             <? $i = 0; ?>
             <? foreach ($pages as $page): ?>
                 <? if (!isset($page['Title'])) continue; ?>
-                <?
-                    /** ensures variables in any .page title are used */
-                    eval("\$title=\"".htmlspecialchars((string)$page['Title'])."\";");
-                ?>
+                <? $title = processTitle($page['Title']); ?>
                 <? $tabId = "tab" . ($i+1); ?>
                 <button
                     role="tab"
@@ -35,6 +32,7 @@
             if (!isset($page['Title'])) {
                 continue;
             }
+            $title = processTitle($page['Title']);
             $tabId = "tab" . ($i+1);
             annotate($page['file']);
         ?>

emhttp/plugins/dynamix/include/DefaultPageLayout/MainContentTabless.php

@@ -11,10 +11,7 @@
 
             <? if (isset($page['Title'])): ?>
                 <div class="title">
-                    <?
-                        /** ensures variables in any .page title are used */
-                        eval("\$title=\"".htmlspecialchars((string)$page['Title'])."\";");
-                    ?>
+                    <? $title = processTitle($page['Title']); ?>
                     <?= tab_title($title, $page['root'], _var($page, 'Tag', false)) ?>
                 </div>
             <? endif; ?>