The Advanced Custom Fields: Extended and Advanced Custom Fields: Extended PRO WordPress plugins from 0.9.2.4 to 0.9.2.7 do not consistently disable shortcode processing in the confirmation message of their front-end forms, allowing unauthenticated visitors to have arbitrary shortcodes executed server-side when they submit a form whose stored configuration does not carry the relevant setting.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
High
Difficult to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1