A vulnerability in the Network-Based Application Recognition (NBAR) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. This vulnerability are due to a parsing issue on DNS packets. An attacker could exploit this vulnerability by sending crafted DNS packets through routers that are running an affected version and have NBAR enabled. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition.

A vulnerability in Performance Routing Version 3 (PfRv3) of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the affected device to reload. The vulnerability is due to the processing of malformed smart probe packets. An attacker could exploit this vulnerability by sending specially crafted smart probe packets at the affected device. A successful exploit could allow the attacker to reload the device, resulting in a denial of service (DoS) attack on an affected system.

A vulnerability in the VLAN Trunking Protocol (VTP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to corrupt the internal VTP database on an affected device and cause a denial of service (DoS) condition. The vulnerability is due to a logic error in how the affected software handles a subset of VTP packets. An attacker could exploit this vulnerability by sending VTP packets in a sequence that triggers a timeout in the VTP message processing code of the affected software. A successful exploit could allow the attacker to impact the ability to create, modify, or delete VLANs and cause a DoS condition. There are workarounds that address this vulnerability. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS Software or Cisco IOS XE Software, are operating in VTP client mode or VTP server mode, and do not have a VTP domain name configured. The default configuration for Cisco devices that ar…

A vulnerability in the wireless controller manager of Cisco IOS XE could allow an unauthenticated, adjacent attacker to cause a restart of the switch and result in a denial of service (DoS) condition. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by submitting a crafted association request. An exploit could allow the attacker to cause the switch to restart. This vulnerability affects Cisco Catalyst 3650 and 3850 switches running IOS XE Software versions 16.1 through 16.3.3, and acting as wireless LAN controllers (WLC). Cisco Bug IDs: CSCvd45069.

A vulnerability in the Cisco Network Plug and Play application of Cisco IOS 12.4 through 15.6 and Cisco IOS XE 3.3 through 16.4 could allow an unauthenticated, remote attacker to gain unauthorized access to sensitive data by using an invalid certificate. The vulnerability is due to insufficient certificate validation by the affected software. An attacker could exploit this vulnerability by supplying a crafted certificate to an affected device. A successful exploit could allow the attacker to conduct man-in-the-middle attacks to decrypt confidential information on user connections to the affected software. Cisco Bug IDs: CSCvc33171.