WordPress iThemes Security Insecure Backup / Logfile Generation
Posted on 22 April 2016
-------------------------------------- ISSUE 1: Wordpress iThemes Security (Better WP Security) Insecure Backup/Logfile Generation (access rights) ================================================================================================== Description =========== A vulnerability has been found in iThemes Security backup function that may allow attackers to gain access to backup/log files. By default, when using the "database backup on filesystem" feature, iThemes Security saves the backup files in a world-readable directory : wp-content/uploads/ithemes-security/backups The .htaccess file is generated during the plugin initial setup/update, only if the wp-content/uploads/ithemes-security/backups exists (or wp-content/uploads/ithemes-security/logs). Note that it does *NOT* exists by default. When running a backup, the ITSEC_Backup class creates the directory but *without* any .htaccess file inside. The same thing happens with log saving. If the webserver has directory listing enabled, then anybody can download the complete database backup or view the log files. **Access Vector**: remote **Security Risk**: high **Vulnerability**: CWE-219 **CVSS Base Score**: 7.5 --------------- Vulnerable code --------------- The vulnerable code is located in core/modules/backup/class-itsec-backup.php, line 246 : if ( ! is_dir( $itsec_globals['ithemes_backup_dir'] ) ) { @mkdir( trailingslashit( $itsec_globals['ithemes_dir'] ) . 'backups' ); } And in core/class-itsec-logger.php, line 31 : //Make sure the logs directory was created if ( ! is_dir( $itsec_globals['ithemes_log_dir'] ) ) { @mkdir( trailingslashit( $itsec_globals['ithemes_dir'] ) . 'logs' ); } The application creates the backup/log directory, but *not* the .htaccess/index file inside. -------- Solution -------- Add a default index file file inside the backup folder when creating the directory or store the backups outside of the web root. Update iThemes Security to version >= 5.3.1 Timeline (dd/mm/yyyy) ===================== * 26/02/2016 : Initial contact with iThemes. * 26/02/2016 : iThemes confirms the vulnerabilities. * 29/02/2016 : iThemes publishes a new version (5.3.1) of iThemes Security that fixes the vulnerabilities. Credits ======= * Nicolas CHATELAIN, Sysdream (n.chatelain -at- sysdream -dot- com) -- SYSDREAM Labs <labs@sysdream.com> GPG : 47D1 E124 C43E F992 2A2E 1551 8EB4 8CD9 D5B2 59A1 * Website: https://sysdream.com/ * Twitter: @sysdream -------------------------------------- ISSUE 2: Wordpress iThemes Security (Better WP Security) Insecure Backup/Logfile Generation (predicatable filename) ========================================================================================================== Description =========== When using the "database backup/logging on filesystem" feature, iThemes security generates a weak filename allowing attackers to obtain the backup/log file if they know when the backup/log file was generated (timestamp). **Access Vector**: remote **Security Risk**: medium **Vulnerability**: CWE-330 **CVSS Base Score**: 7.5 --------------- Vulnerable code --------------- The vulnerable code is located at core/modules/backup/class-itsec-backup.php, line 244 : $file = 'backup-' . substr( sanitize_title( get_bloginfo( 'name' ) ), 0, 20 ) . '-' . $current_time . '-' . ITSEC_Lib::get_random( mt_rand( 5, 10 ) ); In core/class-itsec-logger.php, line : $itsec_globals['settings']['log_info'] = substr( sanitize_title( get_bloginfo( 'name' ) ), 0, 20 ) . '-' . ITSEC_Lib::get_random( mt_rand( 0, 10 ) ); In core/class-itsec-lib.php, function get_random, line 415: public static function get_random( $length, $base32 = false, $special_chars = false ) { if ( true === $base32 ) { $string = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567'; } else { $string = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'; if ( true === $special_chars ) { $string .= '_)(*&^%$#@!~`:;<>,.?/{}[]|'; } } return substr( str_shuffle( $string ), mt_rand( 0, strlen( $string ) - $length ), $length ); } The str_shuffle should *never* be used for generating secure strings as it uses the PHP rand() function and just shuffles the characters' position. -------- Solution -------- Make sure to generate non-predictable strings, using cryptographically secure generators. Update iThemes Security to version >= 5.3.1 Affected versions ================= * iThemes Security <= 5.3.0 Timeline (dd/mm/yyyy) ===================== * 26/02/2016 : Initial contact with iThemes. * 26/02/2016 : iThemes confirms the vulnerabilities. * 29/02/2016 : iThemes publishes a new version (5.3.1) of iThemes Security that fixes the vulnerabilities. Credits ======= * Nicolas CHATELAIN, Sysdream (n.chatelain -at- sysdream -dot- com) -- SYSDREAM Labs <labs@sysdream.com> GPG : 47D1 E124 C43E F992 2A2E 1551 8EB4 8CD9 D5B2 59A1 * Website: https://sysdream.com/ * Twitter: @sysdream
