Unauthenticated administrative read access via invalid Telnet username

Authentication bypass in Sharp and Toshiba Tec MFPs allows remote attackers to gain read-only administrative access through Telnet. The Telnet login handler accepts an overlong invalid username as an administrative account without requiring the corresponding password. Network access to the MFP's Telnet service is required; the resulting session exposes configuration and internal device information but does not grant demonstrated write access.