Mozilla, Firefox, and Opera appear to allow access to the content from one frame from another, allowing for disclosure of the local directory structure. Tested versions include Firefox 1.0, Mozilla 1.7, and Opera 7.51 through 7.54.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/35250/browserFind.txt
Source: https://packetstormsecurity.com/files/35250/browserFind.txt.html