Issue #3457781 by catch, longwave, senscybersecurity, cmlara, cilefen, poker10, greggles, alexpott, ericgsmith, xjm: Maintenance pages leak sensitive environment information

(cherry picked from commit 48b0aea1d5)
(cherry picked from commit 97118bca05)
(cherry picked from commit 3ebfcc8919)

core/includes/errors.inc

@@ -147,7 +147,7 @@ function error_displayable($error = NULL) {
  *   Non-recoverable fatal errors cannot be logged by Drupal.
  */
 function _drupal_log_error($error, $fatal = FALSE) {
-  $is_installer = InstallerKernel::installationAttempted();
+  $is_installer = InstallerKernel::installationAttempted() && \Drupal::hasContainer();
 
   // Backtrace, exception and 'severity_level' are not valid replacement values
   // for t().
@@ -158,7 +158,7 @@ function _drupal_log_error($error, $fatal = FALSE) {
 
   // When running inside the testing framework, we relay the errors
   // to the tested site by the way of HTTP headers.
-  if (DRUPAL_TEST_IN_CHILD_SITE && !headers_sent() && (!defined('SIMPLETEST_COLLECT_ERRORS') || SIMPLETEST_COLLECT_ERRORS)) {
+  if (defined('DRUPAL_TEST_IN_CHILD_SITE') && DRUPAL_TEST_IN_CHILD_SITE && !headers_sent() && (!defined('SIMPLETEST_COLLECT_ERRORS') || SIMPLETEST_COLLECT_ERRORS)) {
     _drupal_error_header($error['@message'], $error['%type'], $error['%function'], $error['%file'], $error['%line']);
   }
 
@@ -174,7 +174,7 @@ function _drupal_log_error($error, $fatal = FALSE) {
       // implementations to use it.
       \Drupal::logger('php')->log($severity, '%type: @message in %function (line %line of %file) @backtrace_string.', $error + ['backtrace' => $backtrace, 'exception' => $exception, 'severity_level' => $severity]);
     }
-    catch (\Exception $e) {
+    catch (\Throwable) {
       // We can't log, for example because the database connection is not
       // available. At least try to log to PHP error log.
       error_log(strtr('Failed to log error: ' . Error::DEFAULT_ERROR_MESSAGE . ' @backtrace_string', $error));
@@ -223,12 +223,16 @@ function _drupal_log_error($error, $fatal = FALSE) {
       }
 
       // Attempt to reduce verbosity by removing DRUPAL_ROOT from the file path
-      // in the message. This does not happen for (false) security.
-      if (\Drupal::hasService('kernel')) {
-        $root_length = strlen(\Drupal::root());
-        if (substr($error['%file'], 0, $root_length) == \Drupal::root()) {
-          $error['%file'] = substr($error['%file'], $root_length + 1);
-        }
+      // in the message. This also prevents full path disclosure, see
+      // https://owasp.org/www-community/attacks/Full_Path_Disclosure.
+      try {
+        $root = \Drupal::root();
+      }
+      catch (\Throwable) {
+        $root = realpath(dirname(__DIR__, 2));
+      }
+      if (str_starts_with($error['%file'], $root)) {
+        $error['%file'] = substr($error['%file'], strlen($root) + 1);
       }
 
       // Check if verbose error reporting is on.
@@ -244,14 +248,13 @@ function _drupal_log_error($error, $fatal = FALSE) {
       }
       else {
         // With verbose logging, we will also include a backtrace.
-
         // First trace is the error itself, already contained in the message.
-        // While the second trace is the error source and also contained in the
-        // message, the message doesn't contain argument values, so we output it
-        // once more in the backtrace.
         array_shift($backtrace);
-        // Generate a backtrace containing only scalar argument values.
-        $error['@backtrace'] = Error::formatBacktrace($backtrace);
+        // Strip arguments from the backtrace.
+        $error['@backtrace'] = Error::formatBacktrace(array_map(function ($trace) {
+          unset($trace['args']);
+          return $trace;
+        }, $backtrace));
         $message = new FormattableMarkup('<details class="error-with-backtrace"><summary>' . Error::DEFAULT_ERROR_MESSAGE . '</summary><pre class="backtrace">@backtrace</pre></details>', $error);
       }
     }
@@ -268,8 +271,13 @@ function _drupal_log_error($error, $fatal = FALSE) {
           '#title' => 'Error',
           '#markup' => $message,
         ];
-        install_display_output($output, $GLOBALS['install_state']);
-        exit;
+        try {
+          install_display_output($output, $GLOBALS['install_state']);
+          exit;
+        }
+        catch (\Throwable) {
+          // The maintenance page failed, so fall back to a plain error message.
+        }
       }
 
       $response->setContent($message);

core/install.php

@@ -43,6 +43,11 @@ if (OpCodeCache::isEnabled() && !ini_get('opcache.save_comments')) {
   exit();
 }
 
+// Set the Drupal custom error handler.
+require_once $root_path . '/core/includes/errors.inc';
+set_error_handler('_drupal_error_handler');
+set_exception_handler('_drupal_exception_handler');
+
 // Start the installer.
 require_once $root_path . '/core/includes/install.core.inc';
 install_drupal($class_loader);

core/modules/system/tests/src/Functional/System/SystemAuthorizeTest.php

@@ -68,4 +68,21 @@ class SystemAuthorizeTest extends BrowserTestBase {
     $this->assertSession()->responseContains('core/misc/states.js');
   }
 
+  /**
+   * Tests error handling in authorize.php.
+   */
+  public function testError(): void {
+    $settings_filename = $this->siteDirectory . '/settings.php';
+    chmod($settings_filename, 0777);
+    $settings_php = file_get_contents($settings_filename);
+    $settings_php .= "\ndefine('SIMPLETEST_COLLECT_ERRORS', FALSE);\n";
+    $settings_php .= "\ntrigger_error('Test warning', E_USER_WARNING);\n";
+    file_put_contents($settings_filename, $settings_php);
+
+    $this->drupalGetAuthorizePHP();
+
+    $this->assertSession()->pageTextContains('User warning: Test warning');
+    $this->assertSession()->pageTextMatches('@line \d+ of sites/simpletest@');
+  }
+
 }