A vulnerability in Cisco ASR 5000 Series Aggregated Services Routers running the Cisco StarOS operating system could allow an authenticated, remote attacker to overwrite or modify sensitive system files. The vulnerability is due to the inclusion of sensitive system files within specific FTP subdirectories. An attacker could exploit this vulnerability by overwriting sensitive configuration files through FTP. An exploit could allow the attacker to overwrite configuration files on an affected system. Cisco Bug IDs: CSCvd47739. Known Affected Releases: 21.0.v0.65839.