CRM/Utils/Check/Component/Security.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 5                                                  |
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   6  | Copyright CiviCRM LLC (c) 2004-2020                                |
   7  +--------------------------------------------------------------------+
   8  | This file is a part of CiviCRM.                                    |
   9  |                                                                    |
  10  | CiviCRM is free software; you can copy, modify, and distribute it  |
  11  | under the terms of the GNU Affero General Public License           |
  12  | Version 3, 19 November 2007 and the CiviCRM Licensing Exception.   |
  13  |                                                                    |
  14  | CiviCRM is distributed in the hope that it will be useful, but     |
  15  | WITHOUT ANY WARRANTY; without even the implied warranty of         |
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  17  | See the GNU Affero General Public License for more details.        |
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  19  | You should have received a copy of the GNU Affero General Public   |
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  22  | at info[AT]civicrm[DOT]org. If you have questions about the        |
  23  | GNU Affero General Public License or the licensing of CiviCRM,     |
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  26  */
  27
  28 /**
  29  *
  30  * @package CRM
  31  * @copyright CiviCRM LLC (c) 2004-2020
  32  */
  33 class CRM_Utils_Check_Component_Security extends CRM_Utils_Check_Component {
  34
  35   /**
  36    * CMS have a different pattern to their default file path and URL.
  37    *
  38    * @todo Use Civi::paths instead?
  39    */
  40   public function getFilePathMarker() {
  41     $config = CRM_Core_Config::singleton();
  42     switch ($config->userFramework) {
  43       case 'Joomla':
  44         return '/media/';
  45
  46       default:
  47         return '/files/';
  48     }
  49   }
  50
  51   /**
  52    * Check if our logfile is directly accessible.
  53    *
  54    * Per CiviCRM default the logfile sits in a folder which is
  55    * web-accessible, and is protected by a default .htaccess
  56    * configuration. If server config causes the .htaccess not to
  57    * function as intended, there may be information disclosure.
  58    *
  59    * The debug log may be jam-packed with sensitive data, we don't
  60    * want that.
  61    *
  62    * Being able to be retrieved directly doesn't mean the logfile
  63    * is browseable or visible to search engines; it means it can be
  64    * requested directly.
  65    *
  66    * @return array
  67    *   Array of messages
  68    * @see CRM-14091
  69    */
  70   public function checkLogFileIsNotAccessible() {
  71     $messages = [];
  72
  73     $config = CRM_Core_Config::singleton();
  74
  75     $log = CRM_Core_Error::createDebugLogger();
  76     $log_filename = str_replace('\\', '/', $log->_filename);
  77
  78     $filePathMarker = $this->getFilePathMarker();
  79
  80     // Hazard a guess at the URL of the logfile, based on common
  81     // CiviCRM layouts.
  82     if ($upload_url = explode($filePathMarker, $config->imageUploadURL)) {
  83       $url[] = $upload_url[0];
  84       if ($log_path = explode($filePathMarker, $log_filename)) {
  85         // CRM-17149: check if debug log path includes $filePathMarker
  86         if (count($log_path) > 1) {
  87           $url[] = $log_path[1];
  88           $log_url = implode($filePathMarker, $url);
  89           if ($this->fileExists($log_url)) {
  90             $docs_url = $this->createDocUrl('checkLogFileIsNotAccessible');
  91             $msg = 'The <a href="%1">CiviCRM debug log</a> should not be downloadable.'
  92               . '<br />' .
  93               '<a href="%2">Read more about this warning</a>';
  94             $messages[] = new CRM_Utils_Check_Message(
  95               __FUNCTION__,
  96               ts($msg, [1 => $log_url, 2 => $docs_url]),
  97               ts('Security Warning'),
  98               \Psr\Log\LogLevel::WARNING,
  99               'fa-lock'
 100             );
 101           }
 102         }
 103       }
 104     }
 105
 106     return $messages;
 107   }
 108
 109   /**
 110    * Check if our uploads directory has accessible files.
 111    *
 112    * We'll test a handful of files randomly. Hazard a guess at the URL
 113    * of the uploads dir, based on common CiviCRM layouts. Try and
 114    * request the files, and if any are successfully retrieved, warn.
 115    *
 116    * Being retrievable doesn't mean the files are browseable or visible
 117    * to search engines; it only means they can be requested directly.
 118    *
 119    * @return array
 120    *   Array of messages
 121    * @see CRM-14091
 122    *
 123    * @todo Test with WordPress, Joomla.
 124    */
 125   public function checkUploadsAreNotAccessible() {
 126     $messages = [];
 127
 128     $config = CRM_Core_Config::singleton();
 129     $privateDirs = [
 130       $config->uploadDir,
 131       $config->customFileUploadDir,
 132     ];
 133
 134     foreach ($privateDirs as $privateDir) {
 135       $heuristicUrl = $this->guessUrl($privateDir);
 136       if ($this->isDirAccessible($privateDir, $heuristicUrl)) {
 137         $messages[] = new CRM_Utils_Check_Message(
 138           __FUNCTION__,
 139           ts('Files in the data directory (<a href="%3">%2</a>) should not be downloadable.'
 140             . '<br />'
 141             . '<a href="%1">Read more about this warning</a>',
 142             [
 143               1 => $this->createDocUrl('checkUploadsAreNotAccessible'),
 144               2 => $privateDir,
 145               3 => $heuristicUrl,
 146             ]),
 147             ts('Private Files Readable'),
 148             \Psr\Log\LogLevel::WARNING,
 149             'fa-lock'
 150         );
 151       }
 152     }
 153
 154     return $messages;
 155   }
 156
 157   /**
 158    * Check if our uploads or ConfigAndLog directories have browseable
 159    * listings.
 160    *
 161    * Retrieve a listing of files from the local filesystem, and the
 162    * corresponding path via HTTP. Then check and see if the local
 163    * files are represented in the HTTP result; if so then warn. This
 164    * MAY trigger false positives (if you have files named 'a', 'e'
 165    * we'll probably match that).
 166    *
 167    * @return array
 168    *   Array of messages
 169    * @see CRM-14091
 170    *
 171    * @todo Test with WordPress, Joomla.
 172    */
 173   public function checkDirectoriesAreNotBrowseable() {
 174     $messages = [];
 175     $config = CRM_Core_Config::singleton();
 176     $publicDirs = [
 177       $config->imageUploadDir => $config->imageUploadURL,
 178     ];
 179
 180     // Setup index.html files to prevent browsing
 181     foreach ($publicDirs as $publicDir => $publicUrl) {
 182       CRM_Utils_File::restrictBrowsing($publicDir);
 183     }
 184
 185     // Test that $publicDir is not browsable
 186     foreach ($publicDirs as $publicDir => $publicUrl) {
 187       if ($this->isBrowsable($publicDir, $publicUrl)) {
 188         $msg = 'Directory <a href="%1">%2</a> should not be browseable via the web.'
 189           . '<br />' .
 190           '<a href="%3">Read more about this warning</a>';
 191         $docs_url = $this->createDocUrl('checkDirectoriesAreNotBrowseable');
 192         $messages[] = new CRM_Utils_Check_Message(
 193           __FUNCTION__,
 194           ts($msg, [1 => $publicDir, 2 => $publicDir, 3 => $docs_url]),
 195           ts('Browseable Directories'),
 196           \Psr\Log\LogLevel::ERROR,
 197           'fa-lock'
 198         );
 199       }
 200     }
 201
 202     return $messages;
 203   }
 204
 205   /**
 206    * Check that some files are not present.
 207    *
 208    * These files have generally been deleted but Civi source tree but could be
 209    * left online if one does a faulty upgrade.
 210    *
 211    * @return array of messages
 212    */
 213   public function checkFilesAreNotPresent() {
 214     global $civicrm_root;
 215
 216     $messages = [];
 217     $files = [
 218       [
 219         // CRM-16005, upgraded from Civi <= 4.5.6
 220         "{$civicrm_root}/packages/dompdf/dompdf.php",
 221         \Psr\Log\LogLevel::CRITICAL,
 222       ],
 223       [
 224         // CRM-16005, Civi >= 4.5.7
 225         "{$civicrm_root}/packages/vendor/dompdf/dompdf/dompdf.php",
 226         \Psr\Log\LogLevel::CRITICAL,
 227       ],
 228       [
 229         // CRM-16005, Civi >= 4.6.0
 230         "{$civicrm_root}/vendor/dompdf/dompdf/dompdf.php",
 231         \Psr\Log\LogLevel::CRITICAL,
 232       ],
 233       [
 234         // CIVI-SA-2013-001
 235         "{$civicrm_root}/packages/OpenFlashChart/php-ofc-library/ofc_upload_image.php",
 236         \Psr\Log\LogLevel::CRITICAL,
 237       ],
 238       [
 239         "{$civicrm_root}/packages/html2text/class.html2text.inc",
 240         \Psr\Log\LogLevel::CRITICAL,
 241       ],
 242     ];
 243     foreach ($files as $file) {
 244       if (file_exists($file[0])) {
 245         $messages[] = new CRM_Utils_Check_Message(
 246           __FUNCTION__,
 247           ts('File \'%1\' presents a security risk and should be deleted.', [1 => $file[0]]),
 248           ts('Unsafe Files'),
 249           $file[1],
 250           'fa-lock'
 251         );
 252       }
 253     }
 254     return $messages;
 255   }
 256
 257   /**
 258    * Discourage use of remote profile forms.
 259    */
 260   public function checkRemoteProfile() {
 261     $messages = [];
 262
 263     if (Civi::settings()->get('remote_profile_submissions')) {
 264       $messages[] = new CRM_Utils_Check_Message(
 265         __FUNCTION__,
 266         ts('Warning: External profile support (aka "HTML Snippet" support) is enabled in <a href="%1">system settings</a>. This setting may be prone to abuse. If you must retain it, consider HTTP throttling or other protections.',
 267           [1 => CRM_Utils_System::url('civicrm/admin/setting/misc', 'reset=1')]
 268         ),
 269         ts('Remote Profiles Enabled'),
 270         \Psr\Log\LogLevel::WARNING,
 271         'fa-lock'
 272       );
 273     }
 274
 275     return $messages;
 276   }
 277
 278   /**
 279    * Check that the sysadmin has not modified the Cxn
 280    * security setup.
 281    */
 282   public function checkCxnOverrides() {
 283     $list = [];
 284     if (defined('CIVICRM_CXN_CA') && CIVICRM_CXN_CA !== 'CiviRootCA') {
 285       $list[] = 'CIVICRM_CXN_CA';
 286     }
 287     if (defined('CIVICRM_CXN_APPS_URL') && CIVICRM_CXN_APPS_URL !== \Civi\Cxn\Rpc\Constants::OFFICIAL_APPMETAS_URL) {
 288       $list[] = 'CIVICRM_CXN_APPS_URL';
 289     }
 290
 291     $messages = [];
 292
 293     if (!empty($list)) {
 294       $messages[] = new CRM_Utils_Check_Message(
 295         __FUNCTION__,
 296         ts('The system administrator has disabled security settings (%1). Connections to remote applications are insecure.', [
 297           1 => implode(', ', $list),
 298         ]),
 299         ts('Security Warning'),
 300         \Psr\Log\LogLevel::WARNING,
 301         'fa-lock'
 302       );
 303     }
 304
 305     return $messages;
 306   }
 307
 308   /**
 309    * Determine whether $url is a public, browsable listing for $dir
 310    *
 311    * @param string $dir
 312    *   Local dir path.
 313    * @param string $url
 314    *   Public URL.
 315    * @return bool
 316    */
 317   public function isBrowsable($dir, $url) {
 318     if (empty($dir) || empty($url) || !is_dir($dir)) {
 319       return FALSE;
 320     }
 321
 322     $result = FALSE;
 323
 324     // this could be a new system with no uploads (yet) -- so we'll make a file
 325     $file = CRM_Utils_File::createFakeFile($dir);
 326
 327     if ($file === FALSE) {
 328       // Couldn't write the file
 329       return FALSE;
 330     }
 331
 332     $content = @file_get_contents("$url");
 333     if (stristr($content, $file)) {
 334       $result = TRUE;
 335     }
 336     unlink("$dir/$file");
 337
 338     return $result;
 339   }
 340
 341   /**
 342    * Determine whether $url is a public version of $dir in which files
 343    * are remotely accessible.
 344    *
 345    * @param string $dir
 346    *   Local dir path.
 347    * @param string $url
 348    *   Public URL.
 349    * @return bool
 350    */
 351   public function isDirAccessible($dir, $url) {
 352     $url = rtrim($url, '/');
 353     if (empty($dir) || empty($url) || !is_dir($dir)) {
 354       return FALSE;
 355     }
 356
 357     $result = FALSE;
 358     $file = CRM_Utils_File::createFakeFile($dir, 'delete me');
 359
 360     if ($file === FALSE) {
 361       // Couldn't write the file
 362       return FALSE;
 363     }
 364
 365     if ($this->fileExists("$url/$file")) {
 366       $content = @file_get_contents("$url/$file");
 367       if (preg_match('/delete me/', $content)) {
 368         $result = TRUE;
 369       }
 370     }
 371
 372     unlink("$dir/$file");
 373
 374     return $result;
 375   }
 376
 377   /**
 378    * @param $topic
 379    *
 380    * @return string
 381    */
 382   public function createDocUrl($topic) {
 383     return CRM_Utils_System::getWikiBaseURL() . $topic;
 384   }
 385
 386   /**
 387    * Make a guess about the URL that corresponds to $targetDir.
 388    *
 389    * @param string $targetDir
 390    *   Local path to a directory.
 391    * @return string
 392    *   a guessed URL for $realDir
 393    */
 394   public function guessUrl($targetDir) {
 395     $filePathMarker = $this->getFilePathMarker();
 396     $config = CRM_Core_Config::singleton();
 397
 398     list($heuristicBaseUrl) = explode($filePathMarker, $config->imageUploadURL);
 399     list(, $heuristicSuffix) = array_pad(explode($filePathMarker, str_replace('\\', '/', $targetDir)), 2, '');
 400     return $heuristicBaseUrl . $filePathMarker . $heuristicSuffix;
 401   }
 402
 403 }