A vulnerability in the DHCP code for the Zero Touch Provisioning feature of Cisco ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a format string vulnerability when processing a crafted DHCP packet for Zero Touch Provisioning. An attacker could exploit this vulnerability by sending a specially crafted DHCP packet to an affected device. An exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco ASR 920 Series Aggregation Services Routers that are running an affected release of Cisco IOS XE Software (3.13 through 3.18) and are listening on the DHCP server port. By default, the devices do not listen on the DHCP server port. Cisco Bug IDs: CSCuy56385.

A vulnerability in the web framework of Cisco IOS XE Software could allow an authenticated, remote attacker to inject arbitrary commands that are executed with root privileges. The vulnerability is due to insufficient input validation of HTTP parameters supplied by the user. An attacker could exploit this vulnerability by authenticating to the device and submitting crafted input to the affected web page parameter. The user must be authenticated to access the affected parameter. A successful exploit could allow the attacker to execute commands with root privileges. This vulnerability affects Cisco devices running Cisco IOS XE Software Release 16.2.1, if the HTTP Server feature is enabled for the device. The newly redesigned, web-based administration interface was introduced in the Denali 16.2 Release of Cisco IOS XE Software. The web-based administration interface in earlier releases of Cisco IOS XE Software is not affected by this vulnerability. Cisco Bug IDs: CSCuy83069.

A vulnerability in the Layer 2 Tunneling Protocol (L2TP) parsing function of Cisco IOS (12.0 through 12.4 and 15.0 through 15.6) and Cisco IOS XE (3.1 through 3.18) could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to insufficient validation of L2TP packets. An attacker could exploit this vulnerability by sending a crafted L2TP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS or Cisco IOS XE Software if the L2TP feature is enabled for the device and the device is configured as an L2TP Version 2 (L2TPv2) or L2TP Version 3 (L2TPv3) endpoint. By default, the L2TP feature is not enabled. Cisco Bug IDs: CSCuy82078.

A vulnerability in the web user interface of Cisco IOS XE 3.1 through 3.17 could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to insufficient resource handling by the affected software when the web user interface is under a high load. An attacker could exploit this vulnerability by sending a high number of requests to the web user interface of the affected software. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. To exploit this vulnerability, the attacker must have access to the management interface of the affected software, which is typically connected to a restricted management network. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS XE Software, if the web user interface of the software is enabled. By default, the web user interface is not enabled. Cisco Bug IDs: CSCup70353.

A vulnerability in the Autonomic Networking Infrastructure (ANI) feature of Cisco IOS Software (15.4 through 15.6) and Cisco IOS XE Software (3.7 through 3.18, and 16) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incomplete input validation on certain crafted packets. An attacker could exploit this vulnerability by sending a crafted IPv6 packet to a device that is running a Cisco IOS Software or Cisco IOS XE Software release that supports the ANI feature. A device must meet two conditions to be affected by this vulnerability: (1) the device must be running a version of Cisco IOS Software or Cisco IOS XE Software that supports ANI (regardless of whether ANI is configured); and (2) the device must have a reachable IPv6 interface. An exploit could allow the attacker to cause the affected device to reload. Cisco Bug IDs: CSCvc42729.

A vulnerability in the Autonomic Networking Infrastructure (ANI) registrar feature of Cisco IOS Software (possibly 15.2 through 15.6) and Cisco IOS XE Software (possibly 3.7 through 3.18, and 16) could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition. The vulnerability is due to incomplete input validation on certain crafted packets. An attacker could exploit this vulnerability by sending a crafted autonomic network channel discovery packet to a device that has all the following characteristics: (1) running a Cisco IOS Software or Cisco IOS XE Software release that supports the ANI feature; (2) configured as an autonomic registrar; (3) has a whitelist configured. An exploit could allow the attacker to cause the affected device to reload. Note: Autonomic networking should be configured with a whitelist. Do not remove the whitelist as a workaround. Cisco Bug IDs: CSCvc42717.

A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or remotely execute code with elevated privileges. The Cluster Management Protocol utilizes Telnet internally as a signaling and command protocol between cluster members. The vulnerability is due to the combination of two factors: (1) the failure to restrict the use of CMP-specific Telnet options only to internal, local communications between cluster members and instead accept and process such options over any Telnet connection to an affected device; and (2) the incorrect processing of malformed CMP-specific Telnet options. An attacker could exploit this vulnerability by sending malformed CMP-specific Telnet options while establishing a Telnet session with an affected Cisco device configured to accept Telnet connections. An exploit could allow an attacker to execute arbitrary code and obtain full control of the device or cause a reload of the affected device. This affects Catalyst switches, Embedded Service 2020 switches, Enhanced Layer 2 EtherSwitch Service Module, Enhanced Layer 2/3 EtherSwitch Service Module, Gigabit Ethernet Switch Module (CGESM) for HP, IE Industrial Ethernet switches, ME 4924-10GE switch, RF Gateway 10, and SM-X Layer 2/3 EtherSwitch Service Module. Cisco Bug IDs: CSCvd48893.

A vulnerability in the handling of list headers in Cisco cBR Series Converged Broadband Routers could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition. Cisco cBR-8 Converged Broadband Routers running vulnerable versions of Cisco IOS XE are affected. More Information: CSCux40637. Known Affected Releases: 15.5(3)S 15.6(1)S. Known Fixed Releases: 15.5(3)S2 15.6(1)S1 15.6(2)S 15.6(2)SP 16.4(1).

A vulnerability in Simple Network Management Protocol (SNMP) functions of Cisco ASR 1000 Series Aggregation Services Routers running Cisco IOS XE Software Release 3.13.6S, 3.16.2S, or 3.17.1S could allow an authenticated, remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. More Information: CSCux68796. Known Affected Releases: 15.5(3)S2.1 15.6(1)S1.1. Known Fixed Releases: 15.4(3)S6.1 15.4(3)S6.2 15.5(3)S2.2 15.5(3)S3 15.6(0.22)S0.23 15.6(1)S2 16.2(0.295) 16.3(0.94) 15.5.3S3.

A vulnerability in the package unbundle utility of Cisco IOS XE Software could allow an authenticated, local attacker to gain write access to some files in the underlying operating system. This vulnerability affects the following products if they are running a vulnerable release of Cisco IOS XE Software: Cisco 5700 Series Wireless LAN Controllers, Cisco Catalyst 3650 Series Switches, Cisco Catalyst 3850 Series Switches, Cisco Catalyst 4500E Series Switches, Cisco Catalyst 4500X Series Switches. More Information: CSCva60013 CSCvb22622. Known Affected Releases: 3.7(0) 16.4.1 Denali-16.1.3 Denali-16.2.2 Denali-16.3.1. Known Fixed Releases: 15.2(4)E3 16.1(2.208) 16.2(2.42) 16.3(1.22) 16.4(0.190) 16.5(0.29).

A vulnerability in the Transaction Language 1 (TL1) code of Cisco ASR 900 Series routers could allow an unauthenticated, remote attacker to cause a reload of, or remotely execute code on, the affected system. This vulnerability affects Cisco ASR 900 Series Aggregation Services Routers (ASR902, ASR903, and ASR907) that are running the following releases of Cisco IOS XE Software: 3.17.0S 3.17.1S 3.17.2S 3.18.0S 3.18.1S. More Information: CSCuy15175. Known Affected Releases: 15.6(1)S 15.6(2)S. Known Fixed Releases: 15.6(1)S2.12 15.6(1.17)S0.41 15.6(1.17)SP 15.6(2)SP 16.4(0.183) 16.5(0.10).

A vulnerability in Cisco IOS XE Software running on Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to cause a configuration integrity change to the vty line configuration on an affected device. This vulnerability affects the following releases of Cisco IOS XE Software running on Cisco cBR-8 Converged Broadband Routers: All 3.16S releases, All 3.17S releases, Release 3.18.0S, Release 3.18.1S, Release 3.18.0SP. More Information: CSCuz62815. Known Affected Releases: 15.5(3)S2.9, 15.6(2)SP. Known Fixed Releases: 15.6(1.7)SP1, 16.4(0.183), 16.5(0.1).

The AAA service in Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 2.1 through 3.18 and 16.2 allows remote attackers to cause a denial of service (device reload) via a failed SSH connection attempt that is mishandled during generation of an error-log message, aka Bug ID CSCuy87667.

Memory leak in the Smart Install client implementation in Cisco IOS 12.2 and 15.0 through 15.2 and IOS XE 3.2 through 3.8 allows remote attackers to cause a denial of service (memory consumption) via crafted image-list parameters, aka Bug ID CSCuy82367.

The DNS forwarder in Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 3.1 through 3.15 allows remote attackers to obtain sensitive information from process memory or cause a denial of service (data corruption or device reload) via a crafted DNS response, aka Bug ID CSCup90532.

Cisco IOS 12.2 and IOS XE 3.14 through 3.16 and 16.1 allow remote attackers to cause a denial of service (device reload) via crafted IP Detail Record (IPDR) packets, aka Bug ID CSCuu35089.

Cisco IOS XE 3.1 through 3.17 and 16.1 through 16.2 allows remote attackers to cause a denial of service (device reload) via crafted ICMP packets that require NAT, aka Bug ID CSCuw85853.

Cisco IOS 12.2 and 15.0 through 15.3 and IOS XE 3.1 through 3.9 allow remote attackers to cause a denial of service (device restart) via a crafted IPv4 Multicast Source Discovery Protocol (MSDP) Source-Active (SA) message, aka Bug ID CSCud36767.

Cisco IOS XE 3.1 through 3.17 and 16.1 on 64-bit platforms allows remote attackers to cause a denial of service (data-structure corruption and device reload) via fragmented IPv4 packets, aka Bug ID CSCux66005.

Cisco IOS 12.2 through 12.4 and 15.0 through 15.6 and IOS XE 3.1 through 3.17 and 16.2 allow remote attackers to cause a denial of service (device reload) via crafted fields in an H.323 message, aka Bug ID CSCux04257.