Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in WatchGuard Fireware OS allows Stored XSS via the Blocked Sites list. This vulnerability requires an authenticated administrator session to a locally managed Firebox.This issue affects Fireware OS: from 12.0 through 12.5.12+701324, from 12.6 through 12.11.