A vulnerability in the web-based user interface (web UI) of Cisco IOS XE Software could allow an authenticated, remote attacker with administrative privileges to read arbitrary files on the underlying filesystem of the device. The vulnerability is due to insufficient file scope limiting. An attacker could exploit this vulnerability by creating a specific file reference on the filesystem and then accessing it through the web UI. An exploit could allow the attacker to read arbitrary files from the underlying operating system's filesystem.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webui-filerd-HngnDYGk