Spoofing using custom cursor and CSS3 hotspot
- February 23, 2007
- David Eckel
- Firefox, SeaMonkey
- Fixed in
- Firefox 126.96.36.199
- Firefox 188.8.131.52
- SeaMonkey 1.0.8
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.
This feature was introduced in Firefox 1.5 and does not affect products based on Mozilla 1.7 or earlier such as Firefox 1.0
Any such spoofing can be made less effective by customizing the appearance of your browser. Right-click on an empty toolbar area and select "Customize..." to move, add, or delete toolbar buttons and other elements.