Opera 7.x up to 7.54, and possibly other versions, allows remote attackers to spoof arbitrary web sites by injecting content from one window into a target window whose name is known but resides in a different domain, as demonstrated using a pop-up window on a trusted web site, aka the "window injection" vulnerability.
Improper Neutralization of Special Elements in Output Used by a Downstream Component The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.