CVE 2009-1684
Cross-site scripting (XSS) vulnerability in WebKit in Apple Safari before 4.0, iPhone OS 1.0 through 2.2.1, and iPhone OS for iPod touch 1.1 through 2.2.1 allows remote attackers to inject arbitrary web script or HTML via an event handler that triggers script execution in the context of the next loaded document.
See the 
CVE page on Mitre.org
for more details.
