Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
International Components for Unicode (ICU) 4.0, 3.6, and other 3.x versions, as used in Apple Mac OS X 10.5 before 10.5.7, iPhone OS 1.0 through 2.2.1, iPhone OS for iPod touch 1.1 through 2.2.1, Fedora 9 and 10, and possibly other operating systems, does not properly handle invalid byte sequences during Unicode conversion, which might allow remote attackers to conduct cross-site scripting (XSS) attacks.
CWE-79 - Cross Site Scripting
Cross-Site Scripting, commonly referred to as XSS, is the most dominant class of vulnerabilities. It allows an attacker to inject malicious code into a pregnable web application and victimize its users. The exploitation of such a weakness can cause severe issues such as account takeover, and sensitive data exfiltration. Because of the prevalence of XSS vulnerabilities and their high rate of exploitation, it has remained in the OWASP top 10 vulnerabilities for years.