The Custom Button Installer dialog in Google Toolbar 4 and 5 beta presents certain domain names in the (1) "Downloaded from" and (2) "Privacy considerations" sections without verifying domain names, which makes it easier for remote attackers to spoof domain names and trick users into installing malicious button XML files, as demonstrated by presenting www.google.com when the button was downloaded from an arbitrary site through an open redirector on www.google.com.

The Google toolbar 1.1.60, when running on Internet Explorer 5.5 and 6.0, allows remote attackers to cause a denial of service (crash with an exception in oleaut32.dll) via malicious HTML, possibly related to small width and height parameters or an incorrect call to the Google.Search() function.