[Security-news] Drupal core - Critical - Arbitrary PHP code execution - SA-CORE-2019-002

[security-news at drupal.org]

View online: https://www.drupal.org/sa-core-2019-002

Project: Drupal core [1]
Date: 2019-January-16
Security risk: *Critical* 16∕25
AC:Complex/A:Admin/CI:All/II:All/E:Theoretical/TD:All [2]
Vulnerability: Arbitrary PHP code execution

Description: 
A remote code execution vulnerability exists in PHP's built-in phar stream
wrapper when performing file operations on an untrusted phar:// URI.

Some Drupal code (core, contrib, and custom) may be performing file
operations on insufficiently validated user input, thereby being exposed to
this vulnerability.

This vulnerability is mitigated by the fact that such code paths typically
require access to an administrative permission or an atypical configuration.

Solution: 
   * If you are using Drupal 8.6.x, upgrade to Drupal 8.6.6 [3].
   * If you are using Drupal 8.5.x or earlier, upgrade to Drupal 8.5.9 [4].
   * If you are using Drupal 7.x, upgrade to Drupal 7.62 [5].

Versions of Drupal 8 prior to 8.5.x are end-of-life and do not receive
security coverage.

.. .phar added to dangerous extensions list

The .phar file extension has been added to Drupal's dangerous extensions
list, which means that any such file uploaded to a Drupal file field will
automatically be converted to a text file (with the .txt extension) to
prevent it from being executed. This is similar to how Drupal handles file
uploads with a .php extension.

.. phar:// stream wrapper disabled by default for Drupal 7 sites on PHP 5.3.2
     and earlier

The replacement stream wrapper is not compatible with PHP versions lower than
5.3.3. Drupal 8 requires a higher PHP version than that, but for Drupal 7
sites using lower PHP versions, the built-in phar stream wrapper has been
disabled rather than replaced. Drupal 7 sites using PHP 5.2 (or PHP
5.3.0-5.3.2) that require phar support will need to re-enable the stream
wrapper for it; however, note that re-enabling the stream wrapper will
re-enable the insecure PHP behavior on those PHP versions.

It is very uncommon to both be running a PHP version lower than 5.3.3 and to
need phar support. If you're in that situation, consider upgrading your PHP
version instead of restoring insecure phar support.

Reported By: 
   * Greg Knaddison  [6] of the Drupal Security Team

Fixed By: 
   * Cash Williams  [7] of the Drupal Security Team
   * Lee Rowlands  [8] of the Drupal Security Team
   * Samuel Mortenson  [9] of the Drupal Security Team
   * Jess   [10] of the Drupal Security Team
   * Alex Pott  [11] of the Drupal Security Team
   * Ted Bowman  [12]
   * Michael Hess  [13] of the Drupal Security Team
   * Alex Bronstein  [14] of the Drupal Security Team
   * Fabian Franz  [15]

-------- ADDITIONAL INFORMATION
----------------------------------------------

Note: Going forward, Drupal core will issue individual security advisories
for separate vulnerabilities included in the release, rather than lumping
"multiple vulnerabilities" into a single advisory. All advisories released
today:

   * SA-CORE-2019-001 [16]
   * SA-CORE-2019-002 [17]

Updating to the latest Drupal core release will apply the fixes for all the
above advisories.


[1] https://www.drupal.org/project/drupal
[2] https://www.drupal.org/security-team/risk-levels
[3] https://www.drupal.org/project/drupal/releases/8.6.6
[4] https://www.drupal.org/project/drupal/releases/8.5.9
[5] https://www.drupal.org/project/drupal/releases/7.62
[6] https://www.drupal.org/user/36762
[7] https://www.drupal.org/user/421070
[8] https://www.drupal.org/user/395439
[9] https://www.drupal.org/user/2582268
[10] https://www.drupal.org/user/65776
[11] https://www.drupal.org/user/157725
[12] https://www.drupal.org/user/240860
[13] https://www.drupal.org/user/102818
[14] https://www.drupal.org/user/78040
[15] https://www.drupal.org/user/693738
[16] https://www.drupal.org/sa-core-2019-001
[17] https://www.drupal.org/sa-core-2019-002