A vulnerability in the OSPF version 3 (OSPFv3) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incomplete input validation of specific OSPFv3 packets. An attacker could exploit this vulnerability by sending a malicious OSPFv3 link-state advertisement (LSA) to an affected device. A successful exploit could allow the attacker to cause the OSPFv3 process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition. Note: The OSPFv3 feature is disabled by default. To exploit this vulnerability, an attacker must be able to establish a full OSPFv3 neighbor state with an affected device. For more information about exploitation conditions, see the Details section of this advisory.

A vulnerability in the Cisco Discovery Protocol service of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause the service to restart, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of Cisco Discovery Protocol messages that are processed by the Cisco Discovery Protocol service. An attacker could exploit this vulnerability by sending a series of malicious Cisco Discovery Protocol messages to an affected device. A successful exploit could allow the attacker to cause the Cisco Discovery Protocol service to fail and restart. In rare conditions, repeated failures of the process could occur, which could cause the entire device to restart.

A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets 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. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. An attacker must have full control of a directly connected device. On Cisco IOS XR devices, the impact is limited to the reload of the UDLD process.

A vulnerability in the implementation of the system login block-for command for Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a login process to unexpectedly restart, causing a denial of service (DoS) condition. This vulnerability is due to a logic error in the implementation of the system login block-for command when an attack is detected and acted upon. An attacker could exploit this vulnerability by performing a brute-force login attack on an affected device. A successful exploit could allow the attacker to cause a login process to reload, which could result in a delay during authentication to the affected device.

A vulnerability in the MPLS Operation, Administration, and Maintenance (OAM) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper input validation when an affected device is processing an MPLS echo-request or echo-reply packet. An attacker could exploit this vulnerability by sending malicious MPLS echo-request or echo-reply packets to an interface that is enabled for MPLS forwarding on the affected device. A successful exploit could allow the attacker to cause the MPLS OAM process to crash and restart multiple times, causing the affected device to reload and resulting in a DoS condition.

A vulnerability in Security Group Tag Exchange Protocol (SXP) in Cisco IOS Software, Cisco IOS XE Software, and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because crafted SXP packets are mishandled. An attacker could exploit this vulnerability by sending specifically crafted SXP packets to the affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

A vulnerability in the Topology Discovery Service of Cisco One Platform Kit (onePK) in Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient length restrictions when the onePK Topology Discovery Service parses Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol message to an affected device. An exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges, or to cause a process crash, which could result in a reload of the device and cause a DoS condition.

A vulnerability in a CLI command related to the virtualization manager (VMAN) in Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying Linux operating system with root privileges. The vulnerability is due to insufficient validation of arguments passed to a specific VMAN CLI command on an affected device. An attacker could exploit this vulnerability by including malicious input as the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system with root privileges, which may lead to complete system compromise. An attacker would need valid administrator credentials to exploit this vulnerability.

A vulnerability in Cisco NX-OS Software and Cisco IOS XE Software could allow an authenticated, local attacker with valid administrator or privilege level 15 credentials to load a virtual service image and bypass signature verification on an affected device. The vulnerability is due to improper signature verification during the installation of an Open Virtual Appliance (OVA) image. An authenticated, local attacker could exploit this vulnerability and load a malicious, unsigned OVA image on an affected device. A successful exploit could allow an attacker to perform code execution on a crafted software OVA image.

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to unexpectedly restart. The vulnerability is due to incorrect validation of the HTTP header of a request that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API on an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition in the NX-API service; however, the NX-OS device itself would still be available and passing network traffic. Note: The NX-API feature is disabled by default.

A vulnerability in the Network Time Protocol (NTP) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to excessive use of system resources when the affected device is logging a drop action for received MODE_PRIVATE (Mode 7) NTP packets. An attacker could exploit this vulnerability by flooding the device with a steady stream of Mode 7 NTP packets. A successful exploit could allow the attacker to cause high CPU and memory usage on the affected device, which could cause internal system processes to restart or cause the affected device to unexpectedly reload. Note: The NTP feature is enabled by default.

A vulnerability in the Link Layer Discovery Protocol (LLDP) implementation for Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition when the device unexpectedly reloads. The vulnerability is due to improper input validation of certain type, length, value (TLV) fields of the LLDP frame header. An attacker could exploit this vulnerability by sending a crafted LLDP packet to an interface on the targeted device. A successful exploit could allow the attacker to cause the switch to reload unexpectedly.

A vulnerability in the authentication, authorization, and accounting (AAA) implementation of Cisco Firepower Extensible Operating System (FXOS) and NX-OS System Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability occurs because AAA processes prevent the NX-OS System Manager from receiving keepalive messages when an affected device receives a high rate of login attempts, such as in a brute-force login attack. System memory can run low on the FXOS devices under the same conditions, which could cause the AAA process to unexpectedly restart or cause the device to reload. An attacker could exploit this vulnerability by performing a brute-force login attack against a device that is configured with AAA security services. A successful exploit could allow the attacker to cause the affected device to reload. This vulnerability affects the following Cisco products if they are running Cisco FXOS or NX-OS System Software that is configured for AAA services: Firepower 4100 Series Next-Generation Firewall, Firepower 9300 Security Appliance, Multilayer Director Switches, Nexus 1000V Series Switches, Nexus 1100 Series Cloud Services Platforms, Nexus 2000 Series Switches, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, Unified Computing System (UCS) 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCuq58760, CSCuq71257, CSCur97432, CSCus05214, CSCux54898, CSCvc33141, CSCvd36971, CSCve03660.

A vulnerability in the Python scripting subsystem of Cisco NX-OS Software could allow an authenticated, local attacker to escape the Python parser and gain unauthorized access to the underlying operating system of the device. The vulnerability exists due to insufficient sanitization of user-supplied parameters that are passed to certain Python functions within the scripting sandbox of the affected device. An attacker could exploit this vulnerability to escape the scripting sandbox and execute arbitrary commands on the underlying operating system with the privileges of the authenticated user. To exploit this vulnerability, an attacker must have local access and be authenticated to the targeted device with administrative or Python execution privileges. These requirements could limit the possibility of a successful exploit. This vulnerability affects the following Cisco products if they are running Cisco NX-OS Software: Multilayer Director Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches - Standalone, NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvb86832, CSCvd86474, CSCvd86479, CSCvd86484, CSCvd86490, CSCve97102, CSCvf12757, CSCvf12804, CSCvf12815, CSCvf15198.

An Access-Control Filtering Mechanisms Bypass vulnerability in certain access-control filtering mechanisms on Cisco Nexus 7000 Series Switches could allow an unauthenticated, remote attacker to bypass defined traffic configured within an access control list (ACL) on the affected system. More Information: CSCtz59354. Known Affected Releases: 5.2(4) 6.1(3)S5 6.1(3)S6 6.2(1.121)S0 7.2(1)D1(1) 7.3(0)ZN(0.161) 7.3(1)N1(0.1). Known Fixed Releases: 7.3(0)D1(1) 6.2(2) 6.1(5) 8.3(0)KMT(0.24) 8.3(0)CV(0.337) 7.3(1)N1(1) 7.3(0)ZN(0.210) 7.3(0)ZN(0.177) 7.3(0)ZD(0.194) 7.3(0)TSH(0.99) 7.3(0)SC(0.14) 7.3(0)RSP(0.7) 7.3(0)N1(1) 7.3(0)N1(0.193) 7.3(0)IZN(0.13) 7.3(0)IB(0.102) 7.3(0)GLF(0.44) 7.3(0)D1(0.178) 7.1(0)D1(0.14) 7.0(3)ITI2(1.6) 7.0(3)ISH1(2.13) 7.0(3)IFD6(0.78) 7.0(3)IFD6(0) 7.0(3)IDE6(0.12) 7.0(3)IDE6(0) 7.0(3)I2(1) 7.0(3)I2(0.315) 7.0(1)ZD(0.3) 7.0(0)ZD(0.84) 6.2(1.149)S0 6.2(0.285) 6.1(5.32)S0 6.1(4.97)S0 6.1(2.30)S0.

Cisco NX-OS 4.0 through 7.3 and 11.0 through 11.2 on 1000v, 2000, 3000, 3500, 5000, 5500, 5600, 6000, 7000, 7700, and 9000 devices allows remote attackers to cause a denial of service (device reload) by leveraging a peer relationship to send a crafted BGP UPDATE message, aka Bug IDs CSCuq77105 and CSCux11417.

Cisco NX-OS 4.0 through 7.3 on Multilayer Director and Nexus 1000V, 2000, 3000, 3500, 4000, 5000, 5500, 5600, 6000, 7000, 7700, and 9000 devices allows remote authenticated users to bypass intended AAA restrictions and obtain privileged CLI access via crafted parameters in an SSH connection negotiation, aka Bug IDs CSCum35502, CSCuw78669, CSCuw79754, and CSCux88492.

Cisco NX-OS 4.1 through 7.3 and 11.0 through 11.2 on Nexus 2000, 5000, 5500, 5600, 6000, 7000, 7700, and 9000 devices allows remote attackers to cause a denial of service (device crash) via crafted IPv4 DHCP packets to the (1) DHCPv4 relay agent or (2) smart relay agent, aka Bug IDs CSCuq24603, CSCur93159, CSCus21693, and CSCut76171.

Buffer overflow in the Smart Call Home implementation in Cisco NX-OS on Fabric Interconnects in Cisco Unified Computing System 1.4 before 1.4(1i), NX-OS 5.0 before 5.0(3)U2(2) on Nexus 3000 devices, NX-OS 4.1 before 4.1(2)E1(1l) on Nexus 4000 devices, NX-OS 5.x before 5.1(3)N1(1) on Nexus 5000 devices, NX-OS 5.2 before 5.2(3a) on Nexus 7000 devices, and CG-OS CG4 before CG4(2) on Connected 1000 Connected Grid Routers allows remote SMTP servers to execute arbitrary code via a crafted reply, aka Bug IDs CSCtk00695, CSCts56633, CSCts56632, CSCts56628, CSCug14405, and CSCuf61322.

The Message Transfer Service (MTS) in Cisco NX-OS before 6.2(7) on MDS 9000 devices and 6.0 before 6.0(2) on Nexus 7000 devices allows remote attackers to cause a denial of service (NULL pointer dereference and kernel panic) via a large volume of crafted traffic, aka Bug ID CSCtw98915.