CVE-2009-1710

WebKit in Apple Safari before 4.0 allows remote attackers to spoof the browser's display of 1 the host name, 2 security indicators, and unspecified other UI elements via a custom cursor in conjunction with a modified CSS3 hotspot property...

Spoofing using custom cursor and CSS3 hotspot — Mozilla

David Eckel reported that browser UI elements--such as the host name and security indicators--could be spoofed by using a large, mostly transparent, custom cursor and adjusting the CSS3 hotspot property so that the visible part of the cursor floated outside the browser content area...