CVE 2010-1393
The Cascading Style Sheets (CSS) implementation in WebKit in Apple Safari before 5.0 on Mac OS X 10.5 through 10.6 and Windows, and before 4.1 on Mac OS X 10.4, allows remote attackers to discover sensitive URLs via an HREF attribute associated with a redirecting URL.
See the 
CVE page on Mitre.org
for more details.
