A vulnerability in the CLI of Cisco IOS XE Software could allow an authenticated, local attacker to write values to the underlying memory of an affected device. The vulnerability is due to improper input validation and authorization of specific commands that a user can execute within the CLI. An attacker could exploit this vulnerability by authenticating to an affected device and issuing a specific set of commands. A successful exploit could allow the attacker to modify the configuration of the device to cause it to be non-secure and abnormally functioning.
The Neighbor Discovery (ND) protocol implementation in the IPv6 stack in Cisco IOS XE 2.1 through 3.17S, IOS XR 2.0.0 through 5.3.2, and NX-OS allows remote attackers to cause a denial of service (packet-processing outage) via crafted ND messages, aka Bug ID CSCuz66542, as exploited in the wild in May 2016.