An Authentication Bypass by Primary Weakness
in the FTP server of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to get limited read-write access to files on the device. When the FTP server is enabled and a user named ftp or anonymous is configured, that user can login without providing the configured password and then has read-write access to their home directory.
This issue affects Junos OS:
The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error.