Google Toolbar allows spoofing the information presented in the dialog which
is being displayed when adding a new Google Toolbar button. This can allow
an attacker to convince the users that his button comes from a trusted
domain. This button can then be used to download malicious files or conduct
phishing attacks (e.g. show a login form of a bank).

Affected versions
* Google Toolbar 5 beta for Internet Explorer 
* Google Toolbar 4 for Internet Explorer 
* Google Toolbar 4 for Firefox (partially)

Technical details:
http://aviv.raffon.net/2007/12/18/GoogleToolbarDialogSpoofingVulnerability.a
spx

--Aviv.