GFI Archiver < 15.13 Stored XSS via FileArchiveAssistantWizard.aspx

GFI Archiver before 15.13 contains a stored cross-site scripting vulnerability in the File Archive Assistant configuration that allows authenticated attackers to inject arbitrary web script or HTML via the excluded extensions parameter to /Archiver/FileArchiveAssistantWizard.aspx. The injected payload is stored by FileArchiveAssistantWizard.btnSave_Click() without output encoding and is executed in the browsers of users who subsequently view the File Archive Assistant settings page.