A vulnerability in the web UI of Cisco IOS XE Software could allow an authenticated, remote attacker to perform a directory traversal and access resources that are outside the filesystem mountpoint of the web UI. This vulnerability is due to an insufficient security configuration. An attacker could exploit this vulnerability by sending a crafted request to the web UI. A successful exploit could allow the attacker to gain read access to files that are outside the filesystem mountpoint of the web UI. Note: These files are located on a restricted filesystem that is maintained for the web UI. There is no ability to write to any files on this filesystem.

A vulnerability in the Cisco IOx application hosting subsystem of Cisco IOS XE Software could allow an authenticated, local attacker to elevate privileges to root on an affected device. This vulnerability is due to insufficient restrictions on the hosted application. An attacker could exploit this vulnerability by logging in to and then escaping the Cisco IOx application container. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges.

A vulnerability in the processing of malformed Common Industrial Protocol (CIP) packets that are sent to Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient input validation during processing of CIP packets. An attacker could exploit this vulnerability by sending a malformed CIP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition.

A vulnerability in the UDP processing functionality of Cisco IOS XE Software for Embedded Wireless Controllers on Catalyst 9100 Series Access Points could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to the improper processing of UDP datagrams. An attacker could exploit this vulnerability by sending malicious UDP datagrams to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper management of memory resources, referred to as a double free. An attacker could exploit this vulnerability by sending crafted SNMP packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. To exploit this vulnerability via SNMP Version 2c or earlier, the attacker must know the SNMP read-only community string for an affected system. To exploit this vulnerability via SNMP Version 3, the attacker must know the user credentials for the affected system. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS XE Software, have been configured to be queried over SNMP, and have Network Address Translation (NAT) enabled. Cisco Bug IDs: CSCve75818.

A vulnerability in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition, or potentially corrupt the BGP routing table, which could result in network instability. The vulnerability exists due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft between IOS XE software releases. When the BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet is received, it could be possible that the IP address length field is miscalculated. An attacker could exploit this vulnerability by sending a crafted BGP packet to an affected device after the BGP session was established. An exploit could allow the attacker to cause the affected device to reload or corrupt the BGP routing table; either outcome would result in a DoS. The vulnerability may be triggered when the router receives a crafted BGP message from a peer on an existing BGP session. This vulnerability affects all releases of Cisco IOS XE Software prior to software release 16.3 that support BGP EVPN configurations. If the device is not configured for EVPN, it is not vulnerable. Cisco Bug IDs: CSCui67191, CSCvg52875.

The DHCP relay subsystem of Cisco IOS 12.2 through 15.6 and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code and gain full control of an affected system. The attacker could also cause an affected system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a buffer overflow condition in the DHCP relay subsystem of the affected software. An attacker could exploit this vulnerability by sending a crafted DHCP Version 4 (DHCPv4) packet to an affected system. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a DoS condition. Cisco Bug IDs: CSCsm45390, CSCuw77959.

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to the improper translation of H.323 messages that use the Registration, Admission, and Status (RAS) protocol and are sent to an affected device via IPv4 packets. An attacker could exploit this vulnerability by sending a crafted H.323 RAS packet through an affected device. A successful exploit could allow the attacker to cause the affected device to crash and reload, resulting in a DoS condition. This vulnerability affects Cisco devices that are configured to use an application layer gateway with NAT (NAT ALG) for H.323 RAS messages. By default, a NAT ALG is enabled for H.323 RAS messages. Cisco Bug IDs: CSCvc57217.