Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Zikula 1.3.0 build #3168 and probably prior has XSS flaw due to improper sanitization of the 'themename' parameter by setting default, modifying and deleting themes. A remote attacker with Zikula administrator privilege could use this flaw to execute arbitrary HTML or web script code in the context of the affected website.
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.