A vulnerability in the authentication, authorization, and accounting (AAA) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass NETCONF or RESTCONF authentication and do either of the following: Install, manipulate, or delete the configuration of an affected device Cause memory corruption that results in a denial of service (DoS) on an affected device This vulnerability is due to an uninitialized variable. An attacker could exploit this vulnerability by sending a series of NETCONF or RESTCONF requests to an affected device. A successful exploit could allow the attacker to use NETCONF or RESTCONF to install, manipulate, or delete the configuration of a network device or to corrupt memory on the device, resulting a DoS.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-aaa-Yx47ZT8Q