A vulnerability in the Cisco Discovery Protocol implementation for Cisco FXOS Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a missing check when the affected software processes Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to exhaust system memory, causing the device to reload. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

A vulnerability within the Endpoint Learning feature of Cisco Nexus 9000 Series Switches running in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an endpoint device in certain circumstances. The vulnerability is due to improper endpoint learning when packets are received on a specific port from outside the ACI fabric and destined to an endpoint located on a border leaf when Disable Remote Endpoint Learning has been enabled. This can result in a Remote (XR) entry being created for the impacted endpoint that will become stale if the endpoint migrates to a different port or leaf switch. This results in traffic not reaching the impacted endpoint until the Remote entry can be relearned by another mechanism.

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco FXOS Software and Cisco NX-OS Software could allow an authenticated, remote attacker to cause the SNMP application on an affected device to restart unexpectedly. The vulnerability is due to improper validation of Abstract Syntax Notation One (ASN.1)-encoded variables in SNMP packets. An attacker could exploit this vulnerability by sending a crafted SNMP packet to the SNMP daemon on the affected device. A successful exploit could allow the attacker to cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition.

A vulnerability in the Link Layer Discovery Protocol (LLDP) subsystem of Cisco Nexus 9000 Series Application Centric Infrastructure (ACI) Mode Switch Software could allow an adjacent, unauthenticated attacker to cause a denial of service (DoS) condition or execute arbitrary code with root privileges. 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 the targeted device. A successful exploit may lead to a buffer overflow condition that could either cause a DoS condition or allow the attacker to execute arbitrary code with root privileges. Note: This vulnerability cannot be exploited by transit traffic through the device; the crafted packet must be targeted to a directly connected interface. This vulnerability affects Cisco Nexus 9000 Series Fabric Switches in ACI mode if they are running a Cisco Nexus 9000 Series ACI Mode Switch Software release prior to 13.2(7f) or any 14.x release.

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the SNMP application to leak system memory, which could cause an affected device to restart unexpectedly. The vulnerability is due to improper error handling when processing inbound SNMP packets. An attacker could exploit this vulnerability by sending multiple crafted SNMP packets to an affected device. A successful exploit could allow the attacker to cause the SNMP application to leak system memory because of an improperly handled error condition during packet processing. Over time, this memory leak could cause the SNMP application to restart multiple times, leading to a system-level restart and a denial of service (DoS) condition.

A vulnerability in the 802.1X implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incomplete input validation of Extensible Authentication Protocol over LAN (EAPOL) frames. An attacker could exploit this vulnerability by sending a crafted EAPOL frame to an interface on the targeted device. A successful exploit could allow the attacker to cause the Layer 2 (L2) forwarding process to restart multiple times, leading to a system-level restart of the device and a DoS condition. Note: This vulnerability affects only NX-OS devices configured with 802.1X functionality. Cisco Nexus 1000V Switch for VMware vSphere devices are affected in versions prior to 5.2(1)SV3(1.4b). Nexus 3000 Series Switches are affected in versions prior to 7.0(3)I7(4). Nexus 3500 Platform Switches are affected in versions prior to 7.0(3)I7(4). Nexus 2000, 5500, 5600, and 6000 Series Switches are affected in versions prior to 7.3(5)N1(1) and 7.1(5)N1(1b). Nexus 7000 and 7700 Series Switches are affected in versions prior to 8.2(3). Nexus 9000 Series Fabric Switches in ACI Mode are affected in versions prior to 13.2(1l). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected in versions prior to 7.0(3)I7(4).

A vulnerability in the Bash shell implementation for Cisco NX-OS Software could allow an authenticated, local attacker to escalate their privilege level by executing commands authorized to other user roles. The attacker must authenticate with valid user credentials. The vulnerability is due to the incorrect implementation of a Bash shell command that allows role-based access control (RBAC) to be bypassed. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the Bash prompt. A successful exploit could allow the attacker to escalate their privilege level by executing commands that should be restricted to other roles. For example, a dev-ops user could escalate their privilege level to admin with a successful exploit of this vulnerability.

A vulnerability in a specific CLI command implementation of Cisco Nexus 9000 Series ACI Mode Switch Software could allow an authenticated, local attacker to escape a restricted shell on an affected device. The vulnerability is due to insufficient sanitization of user-supplied input when issuing a specific CLI command with parameters on an affected device. An attacker could exploit this vulnerability by authenticating to the device CLI and issuing certain commands. A successful exploit could allow the attacker to escape the restricted shell and execute arbitrary commands with root-level privileges on the affected device. This vulnerability only affects Cisco Nexus 9000 Series ACI Mode Switches that are running a release prior to 14.0(3d).

A vulnerability in the Cisco Nexus 9000 Series Fabric Switches running in Application-Centric Infrastructure (ACI) mode could allow an authenticated, local attacker to read arbitrary files on an affected device. The vulnerability is due to a lack of proper input and validation checking mechanisms of user-supplied input sent to an affected device. A successful exploit could allow the attacker unauthorized access to read arbitrary files on an affected device. This vulnerability has been fixed in version 14.0(1h).

A vulnerability in the Internet Group Management Protocol (IGMP) Snooping feature of Cisco NX-OS Software could allow an unauthenticated, adjacent 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 IGMP Snooping subsystem. An attacker could exploit this vulnerability by sending crafted IGMP packets to an affected system. An 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. This vulnerability affects Nexus 2000 Series Switches, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 3600 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode, Nexus 9000 Series Switches in standalone NX-OS mode. Cisco Bug IDs: CSCuv79620, CSCvg71263.