Multiple vulnerabilities in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to inject arbitrary commands into the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell of an affected device and execute commands with root privileges on the device. The vulnerabilities exist because the affected software does not sufficiently sanitize command arguments before passing commands to the Linux shell for execution. An attacker could exploit these vulnerabilities by submitting a malicious CLI command to the affected software. A successful exploit could allow the attacker to break from the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell on an affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCuz03145, CSCuz56419, CSCva31971, CSCvb09542.

A vulnerability in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to gain access to the underlying Linux shell of an affected device and execute arbitrary commands with root privileges on the device. The vulnerability is due to the affected software improperly sanitizing command arguments to prevent access to internal data structures on a device. An attacker who has privileged EXEC mode (privilege level 15) access to an affected device could exploit this vulnerability on the device by executing CLI commands that contain crafted arguments. A successful exploit could allow the attacker to gain access to the underlying Linux shell of the affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCve74432.

A vulnerability in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to gain access to the underlying Linux shell of an affected device and execute arbitrary commands with root privileges on the device. The vulnerability is due to the affected software improperly sanitizing command arguments to prevent access to internal data structures on a device. An attacker who has privileged EXEC mode (privilege level 15) access to an affected device could exploit this vulnerability on the device by executing CLI commands that contain crafted arguments. A successful exploit could allow the attacker to gain access to the underlying Linux shell of the affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCuv91356.

Multiple vulnerabilities in the CLI parser of Cisco IOS XE Software could allow an authenticated, local attacker to inject arbitrary commands into the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell of an affected device and execute commands with root privileges on the device. The vulnerabilities exist because the affected software does not sufficiently sanitize command arguments before passing commands to the Linux shell for execution. An attacker could exploit these vulnerabilities by submitting a malicious CLI command to the affected software. A successful exploit could allow the attacker to break from the CLI of the affected software, which could allow the attacker to gain access to the underlying Linux shell on an affected device and execute arbitrary commands with root privileges on the device. Cisco Bug IDs: CSCuz03145, CSCuz56419, CSCva31971, CSCvb09542.

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.

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS 15.0 through 15.6 and Cisco IOS XE 3.5 through 16.5 could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to how an affected device processes certain IKEv2 packets. An attacker could exploit this vulnerability by sending specific IKEv2 packets to an affected device to be processed. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. This vulnerability affects Cisco devices that have the Internet Security Association and Key Management Protocol (ISAKMP) enabled. Although only IKEv2 packets can be used to trigger this vulnerability, devices that are running Cisco IOS Software or Cisco IOS XE Software are vulnerable when ISAKMP is enabled. A device does not need to be configured with any IKEv2-specific features to be vulnerable. Many features use IKEv2, including different types of VPNs such as the following: LAN-to-LAN VPN; Remote-access VPN, excluding SSL VPN; Dynamic Multipoint VPN (DMVPN); and FlexVPN. Cisco Bug IDs: CSCvc41277.

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.

The Simple Network Management Protocol (SNMP) subsystem of Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 2.2 through 3.17 contains multiple vulnerabilities that could allow an authenticated, remote attacker to remotely execute code on an affected system or cause an affected system to reload. An attacker could exploit these vulnerabilities by sending a crafted SNMP packet to an affected system via IPv4 or IPv6. Only traffic directed to an affected system can be used to exploit these vulnerabilities. The vulnerabilities are due to a buffer overflow condition in the SNMP subsystem of the affected software. The vulnerabilities affect all versions of SNMP: Versions 1, 2c, and 3. To exploit these vulnerabilities via SNMP Version 2c or earlier, the attacker must know the SNMP read-only community string for the affected system. To exploit these vulnerabilities via SNMP Version 3, the attacker must have user credentials for the affected system. All devices that have enabled SNMP and have not explicitly excluded the affected MIBs or OIDs should be considered vulnerable. Cisco Bug IDs: CSCve60376, CSCve78027.

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.

The Zone-Based Firewall (ZBFW) functionality in Cisco IOS, possibly 15.4 and earlier, and IOS XE, possibly 3.13 and earlier, mishandles zone checking for existing sessions, which allows remote attackers to bypass intended resource-access restrictions via spoofed traffic that matches one of these sessions, aka Bug IDs CSCun94946 and CSCun96847.

The server IKEv1 implementation in Cisco IOS 12.2 through 12.4 and 15.0 through 15.6, IOS XE through 3.18S, IOS XR 4.3.x and 5.0.x through 5.2.x, and PIX before 7.0 allows remote attackers to obtain sensitive information from device memory via a Security Association (SA) negotiation request, aka Bug IDs CSCvb29204 and CSCvb36055 or BENIGNCERTAIN.

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.

Cisco IOS XE 2.x and 3.x before 3.10.6S, 3.11.xS through 3.13.xS before 3.13.3S, and 3.14.xS through 3.15.xS before 3.15.1S allows remote attackers to cause a denial of service (device reload) via IPv4 packets that require NAT and MPLS actions, aka Bug ID CSCut96933.

The packet-reassembly implementation in Cisco IOS XE 3.13S and earlier allows remote attackers to cause a denial of service (CPU consumption or packet loss) via fragmented (1) IPv4 or (2) IPv6 packets that trigger ATTN-3-SYNC_TIMEOUT errors after reassembly failures, aka Bug ID CSCuo37957.

The TFTP server in Cisco IOS 12.2(44)SQ1, 12.2(33)XN1, 12.4(25e)JAM1, 12.4(25e)JAO5m, 12.4(23)JY, 15.0(2)ED1, 15.0(2)EY3, 15.1(3)SVF4a, and 15.2(2)JB1 and IOS XE 2.5.x, 2.6.x, 3.1.xS, 3.2.xS, 3.3.xS, 3.4.xS, and 3.5.xS before 3.6.0S; 3.1.xSG, 3.2.xSG, and 3.3.xSG before 3.4.0SG; 3.2.xSE before 3.3.0SE; 3.2.xXO before 3.3.0XO; 3.2.xSQ; 3.3.xSQ; and 3.4.xSQ allows remote attackers to cause a denial of service (device hang or reload) via multiple requests that trigger improper memory management, aka Bug ID CSCts66733.

Cisco IOS XE before 3.7.5S on ASR 1000 devices does not properly handle route adjacencies, which allows remote attackers to cause a denial of service (device hang) via crafted IP packets, aka Bug ID CSCub31873.

Cisco IOS XE 3.5E and earlier on WS-C3850, WS-C3860, and AIR-CT5760 devices does not properly parse the "request system shell" challenge response, which allows local users to obtain Linux root access by leveraging administrative privilege, aka Bug ID CSCur09815.

The Ethernet Connectivity Fault Management (CFM) handling feature in Cisco IOS 12.2(33)SRE9a and earlier and IOS XE 3.13S and earlier allows remote attackers to cause a denial of service (device reload) via malformed CFM packets, aka Bug ID CSCuq93406.

Cisco IOS 12.0, 12.2, 12.4, 15.0, 15.1, 15.2, and 15.3 and IOS XE 2.x and 3.x before 3.7.4S; 3.2.xSE and 3.3.xSE before 3.3.2SE; 3.3.xSG and 3.4.xSG before 3.4.4SG; and 3.8.xS, 3.9.xS, and 3.10.xS before 3.10.1S allow remote attackers to cause a denial of service (device reload) via malformed RSVP packets, aka Bug ID CSCui11547.

The L2TP module in Cisco IOS XE 3.10S(.2) and earlier on ASR 1000 routers allows remote authenticated users to cause a denial of service (ESP card reload) via a malformed L2TP packet, aka Bug ID CSCun09973.