CRM/Utils/Check/Security.php

   1 <?php
   2 /*
   3  +--------------------------------------------------------------------+
   4  | CiviCRM version 4.6                                                |
   5  +--------------------------------------------------------------------+
   6  | Copyright CiviCRM LLC (c) 2004-2015                                |
   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         |
  16  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.               |
  17  | See the GNU Affero General Public License for more details.        |
  18  |                                                                    |
  19  | You should have received a copy of the GNU Affero General Public   |
  20  | License and the CiviCRM Licensing Exception along                  |
  21  | with this program; if not, contact CiviCRM LLC                     |
  22  | at info[AT]civicrm[DOT]org. If you have questions about the        |
  23  | GNU Affero General Public License or the licensing of CiviCRM,     |
  24  | see the CiviCRM license FAQ at http://civicrm.org/licensing        |
  25  +--------------------------------------------------------------------+
  26  */
  27
  28 /**
  29  *
  30  * @package CRM
  31  * @copyright CiviCRM LLC (c) 2004-2015
  32  * $Id: $
  33  *
  34  */
  35 class CRM_Utils_Check_Security {
  36
  37   /**
  38    * CMS have a different pattern to their default file path and URL.
  39    *
  40    * @TODO This function might be better shared in CRM_Utils_Check
  41    * class, but that class doesn't yet exist.
  42    */
  43   public function getFilePathMarker() {
  44     $config = CRM_Core_Config::singleton();
  45     switch ($config->userFramework) {
  46       case 'Joomla':
  47         return '/media/';
  48
  49       default:
  50         return '/files/';
  51     }
  52   }
  53
  54   /**
  55    * Run some sanity checks.
  56    *
  57    * @return array<CRM_Utils_Check_Message>
  58    */
  59   public function checkAll() {
  60     $messages = array_merge(
  61       $this->checkCxnOverrides(),
  62       $this->checkLogFileIsNotAccessible(),
  63       $this->checkUploadsAreNotAccessible(),
  64       $this->checkDirectoriesAreNotBrowseable(),
  65       $this->checkFilesAreNotPresent()
  66     );
  67     return $messages;
  68   }
  69
  70   /**
  71    * Check if our logfile is directly accessible.
  72    *
  73    * Per CiviCRM default the logfile sits in a folder which is
  74    * web-accessible, and is protected by a default .htaccess
  75    * configuration. If server config causes the .htaccess not to
  76    * function as intended, there may be information disclosure.
  77    *
  78    * The debug log may be jam-packed with sensitive data, we don't
  79    * want that.
  80    *
  81    * Being able to be retrieved directly doesn't mean the logfile
  82    * is browseable or visible to search engines; it means it can be
  83    * requested directly.
  84    *
  85    * @return array
  86    *   Array of messages
  87    * @see CRM-14091
  88    */
  89   public function checkLogFileIsNotAccessible() {
  90     $messages = array();
  91
  92     $config = CRM_Core_Config::singleton();
  93
  94     $log = CRM_Core_Error::createDebugLogger();
  95     $log_filename = str_replace('\\', '/', $log->_filename);
  96
  97     $filePathMarker = $this->getFilePathMarker();
  98
  99     // Hazard a guess at the URL of the logfile, based on common
 100     // CiviCRM layouts.
 101     if ($upload_url = explode($filePathMarker, $config->imageUploadURL)) {
 102       $url[] = $upload_url[0];
 103       if ($log_path = explode($filePathMarker, $log_filename)) {
 104         // CRM-17149: check if debug log path includes $filePathMarker
 105         if (count($log_path) > 1) {
 106           $url[] = $log_path[1];
 107           $log_url = implode($filePathMarker, $url);
 108           $headers = @get_headers($log_url);
 109           if (stripos($headers[0], '200')) {
 110             $docs_url = $this->createDocUrl('checkLogFileIsNotAccessible');
 111             $msg = 'The <a href="%1">CiviCRM debug log</a> should not be downloadable.'
 112               . '<br />' .
 113               '<a href="%2">Read more about this warning</a>';
 114             $messages[] = new CRM_Utils_Check_Message(
 115               'checkLogFileIsNotAccessible',
 116               ts($msg, array(1 => $log_url, 2 => $docs_url)),
 117               ts('Security Warning')
 118             );
 119           }
 120         }
 121       }
 122     }
 123
 124     return $messages;
 125   }
 126
 127   /**
 128    * Check if our uploads directory has accessible files.
 129    *
 130    * We'll test a handful of files randomly. Hazard a guess at the URL
 131    * of the uploads dir, based on common CiviCRM layouts. Try and
 132    * request the files, and if any are successfully retrieved, warn.
 133    *
 134    * Being retrievable doesn't mean the files are browseable or visible
 135    * to search engines; it only means they can be requested directly.
 136    *
 137    * @return array
 138    *   Array of messages
 139    * @see CRM-14091
 140    *
 141    * @TODO: Test with WordPress, Joomla.
 142    */
 143   public function checkUploadsAreNotAccessible() {
 144     $messages = array();
 145
 146     $config = CRM_Core_Config::singleton();
 147     $privateDirs = array(
 148       $config->uploadDir,
 149       $config->customFileUploadDir,
 150     );
 151
 152     foreach ($privateDirs as $privateDir) {
 153       $heuristicUrl = $this->guessUrl($privateDir);
 154       if ($this->isDirAccessible($privateDir, $heuristicUrl)) {
 155         $messages[] = new CRM_Utils_Check_Message(
 156           'checkUploadsAreNotAccessible',
 157           ts('Files in the data directory (<a href="%3">%2</a>) should not be downloadable.'
 158             . '<br />'
 159             . '<a href="%1">Read more about this warning</a>',
 160             array(
 161               1 => $this->createDocUrl('checkUploadsAreNotAccessible'),
 162               2 => $privateDir,
 163               3 => $heuristicUrl,
 164             )),
 165           ts('Security Warning')
 166         );
 167       }
 168     }
 169
 170     return $messages;
 171   }
 172
 173   /**
 174    * Check if our uploads or ConfigAndLog directories have browseable
 175    * listings.
 176    *
 177    * Retrieve a listing of files from the local filesystem, and the
 178    * corresponding path via HTTP. Then check and see if the local
 179    * files are represented in the HTTP result; if so then warn. This
 180    * MAY trigger false positives (if you have files named 'a', 'e'
 181    * we'll probably match that).
 182    *
 183    * @return array
 184    *   Array of messages
 185    * @see CRM-14091
 186    *
 187    * @TODO: Test with WordPress, Joomla.
 188    */
 189   public function checkDirectoriesAreNotBrowseable() {
 190     $messages = array();
 191     $config = CRM_Core_Config::singleton();
 192     $publicDirs = array(
 193       $config->imageUploadDir => $config->imageUploadURL,
 194     );
 195
 196     // Setup index.html files to prevent browsing
 197     foreach ($publicDirs as $publicDir => $publicUrl) {
 198       CRM_Utils_File::restrictBrowsing($publicDir);
 199     }
 200
 201     // Test that $publicDir is not browsable
 202     foreach ($publicDirs as $publicDir => $publicUrl) {
 203       if ($this->isBrowsable($publicDir, $publicUrl)) {
 204         $msg = 'Directory <a href="%1">%2</a> should not be browseable via the web.'
 205           . '<br />' .
 206           '<a href="%3">Read more about this warning</a>';
 207         $docs_url = $this->createDocUrl('checkDirectoriesAreNotBrowseable');
 208         $messages[] = new CRM_Utils_Check_Message(
 209           'checkDirectoriesAreNotBrowseable',
 210           ts($msg, array(1 => $publicDir, 2 => $publicDir, 3 => $docs_url)),
 211           ts('Security Warning')
 212         );
 213       }
 214     }
 215
 216     return $messages;
 217   }
 218
 219
 220   /**
 221    * Check that some files are not present.
 222    *
 223    * These files have generally been deleted but Civi source tree but could be
 224    * left online if one does a faulty upgrade.
 225    *
 226    * @return array of messages
 227    */
 228   public function checkFilesAreNotPresent() {
 229     global $civicrm_root;
 230
 231     $messages = array();
 232     $files = array(
 233       "{$civicrm_root}/packages/dompdf/dompdf.php", // CRM-16005, upgraded from Civi <= 4.5.6
 234       "{$civicrm_root}/packages/vendor/dompdf/dompdf/dompdf.php", // CRM-16005, Civi >= 4.5.7
 235       "{$civicrm_root}/vendor/dompdf/dompdf/dompdf.php", // CRM-16005, Civi >= 4.6.0
 236     );
 237     foreach ($files as $file) {
 238       if (file_exists($file)) {
 239         $messages[] = new CRM_Utils_Check_Message(
 240           'checkFilesAreNotPresent',
 241           ts('File \'%1\' presents a security risk and should be deleted.', array(1 => $file)),
 242           ts('Security Warning')
 243         );
 244       }
 245     }
 246     return $messages;
 247   }
 248
 249   /**
 250    * Check that the sysadmin has not modified the Cxn
 251    * security setup.
 252    */
 253   public function checkCxnOverrides() {
 254     $list = array();
 255     if (defined('CIVICRM_CXN_CA') && CIVICRM_CXN_CA !== 'CiviRootCA') {
 256       $list[] = 'CIVICRM_CXN_CA';
 257     }
 258     if (defined('CIVICRM_CXN_APPS_URL') && CIVICRM_CXN_APPS_URL !== \Civi\Cxn\Rpc\Constants::OFFICIAL_APPMETAS_URL) {
 259       $list[] = 'CIVICRM_CXN_APPS_URL';
 260     }
 261
 262     $messages = array();
 263
 264     if (!empty($list)) {
 265       $messages[] = new CRM_Utils_Check_Message(
 266         'checkCxnOverrides',
 267         ts('The system administrator has disabled security settings (%1). Connections to remote applications are insecure.', array(
 268           1 => implode(', ', $list),
 269         )),
 270         ts('Security Warning')
 271       );
 272     }
 273
 274     return $messages;
 275   }
 276
 277   /**
 278    * Determine whether $url is a public, browsable listing for $dir
 279    *
 280    * @param string $dir
 281    *   Local dir path.
 282    * @param string $url
 283    *   Public URL.
 284    * @return bool
 285    */
 286   public function isBrowsable($dir, $url) {
 287     if (empty($dir) || empty($url) || !is_dir($dir)) {
 288       return FALSE;
 289     }
 290
 291     $result = FALSE;
 292     $file = 'delete-this-' . CRM_Utils_String::createRandom(10, CRM_Utils_String::ALPHANUMERIC);
 293
 294     // this could be a new system with no uploads (yet) -- so we'll make a file
 295     file_put_contents("$dir/$file", "delete me");
 296     $content = @file_get_contents("$url");
 297     if (stristr($content, $file)) {
 298       $result = TRUE;
 299     }
 300     unlink("$dir/$file");
 301
 302     return $result;
 303   }
 304
 305   /**
 306    * Determine whether $url is a public version of $dir in which files
 307    * are remotely accessible.
 308    *
 309    * @param string $dir
 310    *   Local dir path.
 311    * @param string $url
 312    *   Public URL.
 313    * @return bool
 314    */
 315   public function isDirAccessible($dir, $url) {
 316     $dir = rtrim($dir, '/');
 317     $url = rtrim($url, '/');
 318     if (empty($dir) || empty($url) || !is_dir($dir)) {
 319       return FALSE;
 320     }
 321
 322     $result = FALSE;
 323     $file = 'delete-this-' . CRM_Utils_String::createRandom(10, CRM_Utils_String::ALPHANUMERIC);
 324
 325     // this could be a new system with no uploads (yet) -- so we'll make a file
 326     file_put_contents("$dir/$file", "delete me");
 327
 328     $headers = @get_headers("$url/$file");
 329     if (stripos($headers[0], '200')) {
 330       $content = @file_get_contents("$url/$file");
 331       if (preg_match('/delete me/', $content)) {
 332         $result = TRUE;
 333       }
 334     }
 335
 336     unlink("$dir/$file");
 337
 338     return $result;
 339   }
 340
 341   /**
 342    * @param $topic
 343    *
 344    * @return string
 345    */
 346   public function createDocUrl($topic) {
 347     return CRM_Utils_System::getWikiBaseURL() . $topic;
 348   }
 349
 350   /**
 351    * Make a guess about the URL that corresponds to $targetDir.
 352    *
 353    * @param string $targetDir
 354    *   Local path to a directory.
 355    * @return string
 356    *   a guessed URL for $realDir
 357    */
 358   public function guessUrl($targetDir) {
 359     $filePathMarker = $this->getFilePathMarker();
 360     $config = CRM_Core_Config::singleton();
 361
 362     list ($heuristicBaseUrl, $ignore) = explode($filePathMarker, $config->imageUploadURL);
 363     list ($ignore, $heuristicSuffix) = explode($filePathMarker, str_replace('\\', '/', $targetDir));
 364     return $heuristicBaseUrl . $filePathMarker . $heuristicSuffix;
 365   }
 366
 367 }