Reflected XSS through an IMG element in Cerberus FTP Server prior to versions 11.0.1 and 10.0.17 allows a remote attacker to execute arbitrary JavaScript or HTML via a crafted public folder URL. This occurs because of the folder_up.png IMG element not properly sanitizing user-inserted directory paths. The path modification must be done on a publicly shared folder for a remote attacker to insert arbitrary JavaScript or HTML. The vulnerability impacts anyone who clicks the malicious link crafted by the attacker.