The XML-RPC system allowed a large number of calls to the same method to be made at once, which could be used as an enabling factor in brute force attacks (for example, attempting to determine user passwords by submitting a large number of password variations at once).
This vulnerability is mitigated by the fact that you must have enabled a module that provides an XML-RPC method that was vulnerable to brute-forcing. There are no such modules in Drupal 7 core, but Drupal 6 core is vulnerable via the Blog API module. It is additionally mitigated if flood control protection is in place for the method in question.
Part of security release SA-CORE-2016-001
This vulnerability affects the following application versions:
- Drupal 6.0
- Drupal 6.1
- Drupal 6.2
- Drupal 6.3
- Drupal 6.4
- Drupal 6.5
- Drupal 6.6
- Drupal 6.7
- Drupal 6.8
- Drupal 6.9
- Drupal 6.10
- Drupal 6.11
- Drupal 6.12
- Drupal 6.13
- Drupal 6.14
- Drupal 6.15
- Drupal 6.16
- Drupal 6.17
- Drupal 6.18
- Drupal 6.19
- Drupal 6.20
- Drupal 6.21
- Drupal 6.22
- Drupal 6.23
- Drupal 6.24
- Drupal 6.25
- Drupal 6.26
- Drupal 6.27
- Drupal 6.28
- Drupal 6.29
- Drupal 6.30
- Drupal 6.31
- Drupal 6.32
- Drupal 6.33
- Drupal 6.34
- Drupal 6.35
- Drupal 6.36
- Drupal 6.37
- Drupal 7.0
- Drupal 7.1
- Drupal 7.2
- Drupal 7.3
- Drupal 7.4
- Drupal 7.5
- Drupal 7.6
- Drupal 7.7
- Drupal 7.8
- Drupal 7.9
- Drupal 7.10
- Drupal 7.11
- Drupal 7.12
- Drupal 7.13
- Drupal 7.14
- Drupal 7.15
- Drupal 7.16
- Drupal 7.17
- Drupal 7.18
- Drupal 7.19
- Drupal 7.20
- Drupal 7.21
- Drupal 7.22
- Drupal 7.23
- Drupal 7.24
- Drupal 7.25
- Drupal 7.26
- Drupal 7.27
- Drupal 7.28
- Drupal 7.29
- Drupal 7.30
- Drupal 7.31
- Drupal 7.32
- Drupal 7.33
- Drupal 7.34
- Drupal 7.35
- Drupal 7.36
- Drupal 7.37
- Drupal 7.38
- Drupal 7.39
- Drupal 7.40
- Drupal 7.41
- Drupal 7.42