CVE-2005-2266: Undefined Security Weakness

Firefox before 1.0.5 and Mozilla before 1.7.9 allows a child frame to call top.focus and other methods in a parent frame, even when the parent is in a different domain, which violates the same origin policy and allows remote attackers to steal sensitive information such as cookies and passwords...

Same origin violation: frame calling top.focus() — Mozilla

A child frame can call top.focus even if the framing page comes from a different origin and has overridden the focus routine. The call is made in the context of the child frame. The attacker would look for a target site with a framed page that makes this call but doesn't verify that its parent...