From The Register, anyone with a valid VeriSign SSL site certificate can forge any other VeriSign SSL site certificate in IE and Konqueror:
A chain is formed when an intermediate certificate is trusted between server and client. Supposedly, the intermediate is accepted only if it’s signed by the certificate authority as safe for the purpose. If it’s merely signed by another certificate’s key, it ought not to be trusted, or at least the user should be warned. Unfortunately, due to a preposterous security engineering oversight, IE and Konqueror don't bother to check this [&hellip]
Mozilla isn’t affected, as usual, though the author chides Mozilla as if maybe it’s a Mozilla quirk that is preventing the exploit. I would hope that The Register’s authors wouldn’t have such uninformed preconceptions :-/.