Asset Builder allows CiviCRM and its extensions to generate dynamic assets. A vulnerability allowed third-parties to trick it into generating assets with unintended inputs.
Exploiting this vulnerability depends on several details (e.g. the asset data-types, input-parameters, and web-domain policies). For the specific assets and configurations that we tested, attacks were substantively constrained by the browsers' "Same Origin Policy". However, other assets and other configurations could be impacted more severely.
CiviCRM version 5.56.1 (and earlier), 5.51.3 (and earlier)
CiviCRM version 5.57.0, 5.56.2, 5.51.4 (ESR)
CiviCRM version 5.57.0, 5.56.2, 5.51.4 (ESR)
Tim Otten, Seamus Lee
security/core#157