HTTP/2 Rapid reset attack The HTTP/2 protocol allows clients to indicate to the server that a previous stream should be canceled by sending a RSTSTREAM frame. The protocol does not require the client and server to coordinate the cancellation in any way, the client may do it unilaterally. The client may also assume that the cancellation will take effect immediately when the server receives the RSTSTREAM frame, before any other data from that TCP connection is processed.

Abuse of this feature is called a Rapid Reset attack because it relies on the ability for an endpoint to send a RSTSTREAM frame immediately after sending a request frame, which makes the other endpoint start working and then rapidly resets the request. The request is canceled, but leaves the HTTP/2 connection open.

The HTTP/2 Rapid Reset attack built on this capability is simple: The client opens a large number of streams at once as in the standard HTTP/2 attack, but rather than waiting for a response to each request stream from the server or proxy, the client cancels each request immediately.

The ability to reset streams immediately allows each connection to have an indefinite number of requests in flight. By explicitly canceling the requests, the attacker never exceeds the limit on the number of concurrent open streams. The number of in-flight requests is no longer dependent on the round-trip time (RTT), but only on the available network bandwidth.

In a typical HTTP/2 server implementation, the server will still have to do significant amounts of work for canceled requests, such as allocating new stream data structures, parsing the query and doing header decompression, and mapping the URL to a resource. For reverse proxy implementations, the request may be proxied to the backend server before the RSTSTREAM frame is processed. The client on the other hand paid almost no costs for sending the requests. This creates an exploitable cost asymmetry between the server and the client.

Multiple software artifacts implementing HTTP/2 are affected. This advisory was originally ingested from the swift-nio-http2 repo advisory and their original conent follows.

swift-nio-http2 specific advisory swift-nio-http2 is vulnerable to a denial-of-service vulnerability in which a malicious client can create and then reset a large number of HTTP/2 streams in a short period of time. This causes swift-nio-http2 to commit to a large amount of expensive work which it then throws away, including creating entirely new Channels to serve the traffic. This can easily overwhelm an EventLoop and prevent it from making forward progress.

swift-nio-http2 1.28 contains a remediation for this issue that applies reset counter using a sliding window. This constrains the number of stream resets that may occur in a given window of time. Clients violating this limit will have their connections torn down. This allows clients to continue to cancel streams for legitimate reasons, while constraining malicious actors.

A Denial of Service vulnerability in the remote login functionality for Cisco NX-OS Software running on Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause a process used for login to terminate unexpectedly and the login attempt to fail. There is no impact to user traffic flowing through the device. The attacker could use either a Telnet or an SSH client for the remote login attempt. Affected Products: This vulnerability affects Cisco Nexus 9000 Series Switches that are running Cisco NX-OS Software and are configured to allow remote Telnet connections to the device. More Information: CSCuy25824. Known Affected Releases: 7.0(3)I3(1) 8.3(0)CV(0.342) 8.3(0)CV(0.345). Known Fixed Releases: 8.3(0)CV(0.362) 8.0(1) 7.0(3)IED5(0.19) 7.0(3)IED5(0) 7.0(3)I4(1) 7.0(3)I4(0.8) 7.0(3)I2(2e) 7.0(3)F1(1.22) 7.0(3)F1(1) 7.0(3)F1(0.230).

A Denial of Service vulnerability in the Telnet remote login functionality of Cisco NX-OS Software running on Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause a Telnet process used for login to terminate unexpectedly and the login attempt to fail. There is no impact to user traffic flowing through the device. Affected Products: This vulnerability affects Cisco Nexus 9000 Series Switches that are running Cisco NX-OS Software and are configured to allow remote Telnet connections to the device. More Information: CSCux46778. Known Affected Releases: 7.0(3)I3(0.170). Known Fixed Releases: 7.0(3)I3(1) 7.0(3)I3(0.257) 7.0(3)I3(0.255) 7.0(3)I2(2e) 7.0(3)F1(1.22) 7.0(3)F1(1).

Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.

IP-in-IP protocol specifies IP Encapsulation within IP standard (RFC 2003, STD 1) that decapsulate and route IP-in-IP traffic is vulnerable to spoofing, access-control bypass and other unexpected behavior due to the lack of validation to verify network packets before decapsulation and routing.

A vulnerability in the Link Layer Discovery Protocol (LLDP) feature of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of specific fields in an LLDP frame. An attacker could exploit this vulnerability by sending a crafted LLDP packet to an interface of an affected device and having an authenticated user retrieve LLDP statistics from the affected device through CLI show commands or Simple Network Management Protocol (SNMP) requests. A successful exploit could allow the attacker to cause the LLDP service to crash and stop running on the affected device. In certain situations, the LLDP crash may result in a reload of the affected device. Note: LLDP is a Layer 2 link protocol. To exploit this vulnerability, an attacker would need to be directly connected to an interface of an affected device, either physically or logically (for example, through a Layer 2 Tunnel configured to transport the LLDP protocol).

A vulnerability in the access control list (ACL) programming for port channel subinterfaces of Cisco Nexus 3000 and 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, remote attacker to send traffic that should be blocked through an affected device. This vulnerability is due to incorrect hardware programming that occurs when configuration changes are made to port channel member ports. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to access network resources that should be protected by an ACL that was applied on port channel subinterfaces.

A vulnerability in the network-operator user role implementation for Cisco NX-OS System Software could allow an authenticated, local attacker to improperly delete valid user accounts. The network-operator role should not be able to delete other configured users on the device. The vulnerability is due to a lack of proper role-based access control (RBAC) checks for the actions that a user with the network-operator role is allowed to perform. An attacker could exploit this vulnerability by authenticating to the device with user credentials that give that user the network-operator role. Successful exploitation could allow the attacker to impact the integrity of the device by deleting configured user credentials. The attacker would need valid user credentials for the device. This vulnerability affects the following Cisco products running Cisco NX-OS System Software: Nexus 3000 Series Switches, Nexus 3600 Platform Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvg21120.

A vulnerability in the Simple Network Management Protocol (SNMP) input packet processor of 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 SNMP protocol data units (PDUs) in SNMP packets. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an 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. 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCuw99630, CSCvg71290, CSCvj67977.

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.

A vulnerability in role-based access control (RBAC) for Cisco NX-OS Software could allow an authenticated, remote attacker to execute CLI commands that should be restricted for a nonadministrative user. The attacker would have to possess valid user credentials for the device. The vulnerability is due to incorrect RBAC privilege assignment for certain CLI commands. An attacker could exploit this vulnerability by authenticating to a device as a nonadministrative user and executing specific commands from the CLI. An exploit could allow the attacker to run commands that should be restricted to administrative users. These commands could modify the configuration or boot image on the device. This vulnerability affects MDS 9000 Series Multilayer Switches, 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvd77904.

A vulnerability in the write-erase feature of Cisco FXOS Software and Cisco NX-OS Software could allow an authenticated, local attacker to configure an unauthorized administrator account for an affected device. The vulnerability exists because the affected software does not properly delete sensitive files when certain CLI commands are used to clear the device configuration and reload a device. An attacker could exploit this vulnerability by logging into an affected device as an administrative user and configuring an unauthorized account for the device. The account would not require a password for authentication and would be accessible only via a Secure Shell (SSH) connection to the device. A successful exploit could allow the attacker to configure an unauthorized account that has administrative privileges, does not require a password for authentication, and does not appear in the running configuration or the audit logs for the affected device. This vulnerability affects Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, Nexus 1000V Series Switches, Nexus 1100 Series Cloud Services Platforms, Nexus 2000 Series Fabric Extenders, Nexus 3500 Platform Switches, Nexus 4000 Series Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvd13993, CSCvd34845, CSCvd34857, CSCvd34862, CSCvd34879, CSCve35753.

A vulnerability in the Border Gateway Protocol (BGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the device unexpectedly reloading. The vulnerability is due to incomplete input validation of the BGP update messages. An attacker could exploit this vulnerability by sending a crafted BGP update message to the targeted device. An exploit could allow the attacker to cause the switch to reload unexpectedly. The Cisco implementation of the BGP protocol only accepts incoming BGP traffic from explicitly defined peers. To exploit this vulnerability, an attacker must be able to send the malicious packets over a TCP connection that appears to come from a trusted BGP peer or inject malformed messages into the victim's BGP network. This would require obtaining information about the BGP peers in the affected system's trusted network. The vulnerability may be triggered when the router receives a malformed BGP message from a peer on an existing BGP session. At least one BGP neighbor session must be established for a router to be vulnerable. 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, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCve79599, CSCve87784, CSCve91371, CSCve91387.

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, local attacker to perform a command-injection attack on an affected device. The vulnerability is due to insufficient input validation of command arguments. An attacker could exploit this vulnerability by injecting malicious command arguments into a vulnerable CLI command. A successful exploit could allow the attacker, authenticated as a privileged user, to execute arbitrary commands with root privileges. Note: On products that support multiple virtual device contexts (VDC), this vulnerability could allow an attacker to access files from any VDC. This vulnerability affects Nexus 2000 Series Fabric Extenders, 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCve51704, CSCve91749, CSCve91768.

A vulnerability in the NX-API management application programming interface (API) in devices running, or based on, Cisco NX-OS Software could allow an authenticated, remote attacker to execute commands with elevated privileges. The vulnerability is due to a failure to properly validate certain parameters included within an NX-API request. An attacker that can successfully authenticate to the NX-API could submit a request designed to bypass NX-OS role assignment. A successful exploit could allow the attacker to execute commands with elevated privileges. This vulnerability affects the following if configured to use the NX-API feature: MDS 9000 Series Multilayer Switches, Nexus 2000 Series Switches, Nexus 3000 Series Switches, Nexus 3500 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 Switches in standalone NX-OS mode. Cisco Bug IDs: CSCvc73177, CSCve40903, CSCve40911.

A vulnerability in the Cisco Discovery Protocol component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code as root or cause a denial of service (DoS) condition on the affected device. The vulnerability exists because of insufficiently validated Cisco Discovery Protocol packet headers. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to a Layer 2 adjacent affected device. A successful exploit could allow the attacker to cause a buffer overflow that could allow the attacker to execute arbitrary code as root or cause a DoS condition on the affected device. This vulnerability affects the following if configured to use Cisco Discovery Protocol: Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 1000V Series Switches, Nexus 1100 Series Cloud Services Platforms, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 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, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvc22202, CSCvc22205, CSCvc22208, CSCvc88078, CSCvc88150, CSCvc88159, CSCvc88162, CSCvc88167.

A vulnerability in the CLI parser of Cisco NX-OS Software could allow an authenticated, local attacker to perform a command-injection attack on an affected device. The vulnerability is due to insufficient input validation of command arguments. An attacker could exploit this vulnerability by injecting malicious command arguments into a vulnerable CLI command. A successful exploit could allow the attacker to execute arbitrary commands with root privileges on the affected device. Note: This vulnerability requires that any feature license is uploaded to the device. The vulnerability does not require that the license be used. This vulnerability affects MDS 9000 Series Multilayer Switches, Nexus 1000V Series Switches, Nexus 1100 Series Cloud Services Platforms, Nexus 2000 Series Fabric Extenders, 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCve51693, CSCve91634, CSCve91659, CSCve91663.

A vulnerability in the implementation of a specific CLI command and the associated Simple Network Management Protocol (SNMP) MIB for Cisco NX-OS (in standalone NX-OS mode) on Cisco Nexus 3000 and 9000 Series Switches could allow an authenticated, remote attacker to exhaust system memory on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to the incorrect implementation of the CLI command, resulting in a failure to free all allocated memory upon completion. An attacker could exploit this vulnerability by authenticating to the affected device and repeatedly issuing a specific CLI command or sending a specific SNMP poll request for a specific Object Identifier (OID). A successful exploit could allow the attacker to cause the IP routing process to restart or to cause a device reset, resulting in a DoS condition. Cisco Bug IDs: CSCvf23136.

A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to obtain sensitive information from memory or cause a denial of service (DoS) condition on the affected product. The vulnerability exists because the affected software insufficiently validates header values in Cisco Fabric Services packets. An attacker could exploit this vulnerability by sending a crafted Cisco Fabric Services packet to an affected device. A successful exploit could allow the attacker to cause a buffer overread condition, which could allow the attacker to obtain sensitive information from memory or cause a DoS condition on the affected product. This vulnerability affects Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvd69957, CSCve02435, CSCve04859, CSCve41536, CSCve41538, CSCve41559.

A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability exists because the affected software insufficiently validates Cisco Fabric Services packets when the software processes packet data. An attacker could exploit this vulnerability by sending a maliciously crafted Cisco Fabric Services packet to an affected device. A successful exploit could allow the attacker to cause a buffer overflow condition on the device, which could cause process crashes and result in a DoS condition on the device. This vulnerability affects Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvd69960, CSCve02463, CSCve04859, CSCve41530, CSCve41537, CSCve41541, CSCve41557.

A vulnerability in the NX-API feature of Cisco NX-OS Software could allow an authenticated, remote attacker to send a malicious packet to the management interface on an affected system and execute a command-injection exploit. The vulnerability is due to incorrect input validation of user-supplied data to the NX-API subsystem. An attacker could exploit this vulnerability by sending a malicious HTTP or HTTPS packet to the management interface of an affected system that has the NX-API feature enabled. A successful exploit could allow the attacker to execute arbitrary commands with root privileges. Note: NX-API is disabled by default. This vulnerability affects MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 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 Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules. Cisco Bug IDs: CSCvd47415, CSCve03216, CSCve03224, CSCve03234.

A vulnerability in the Cisco Discovery Protocol (formerly known as CDP) subsystem of devices running, or based on, Cisco NX-OS Software contain a vulnerability that could allow an unauthenticated, adjacent attacker to create a denial of service (DoS) condition. The vulnerability is due to a failure to properly validate certain fields within a Cisco Discovery Protocol message prior to processing it. An attacker with the ability to submit a Cisco Discovery Protocol message designed to trigger the issue could cause a DoS condition on an affected device while the device restarts. This vulnerability affects Firepower 4100 Series Next-Generation Firewall, Firepower 9300 Security Appliance, MDS 9000 Series 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 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 Switches in NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvc89242, CSCve40943, CSCve40953, CSCve40965, CSCve40970, CSCve40978, CSCve40992, CSCve41000, CSCve41007.

A vulnerability in the DHCPv6 feature of the Cisco Nexus 9000 Series Fabric Switches in Application-Centric Infrastructure (ACI) Mode could allow an unauthenticated, remote attacker to cause the device to run low on system memory, which could result in a Denial of Service (DoS) condition on an affected system. The vulnerability is due to improper memory management when DHCPv6 packets are received on an interface of the targeted device. An attacker could exploit this vulnerability by sending a high number of malicious DHCPv6 packets to be processed by an affected device. A successful exploit could allow the attacker to cause the system to run low on memory, which could cause an eventual reboot of an affected device. The vulnerability only applies to IPv6 protocol packets and not for IPv4 protocol packets. This vulnerability affects Cisco Nexus 9000 Series Fabric Switches in ACI Mode running software version 13.0(1k). The vulnerability can only be exploited when unicast routing is enabled on the Bridge Domain (BD). DHCP and DHCP relay do not have to be configured for the vulnerability to be exploited. Cisco Bug IDs: CSCvg38918.

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system of an affected device. The vulnerability is due to insufficient validation of arguments passed to certain CLI commands. 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 operating system with elevated privileges. An attacker would need valid administrator credentials to exploit this vulnerability. MDS 9000 Series Multilayer Switches are affected running software versions prior to 6.2(27) and 8.2(3). Nexus 3000 Series Switches are affected running software versions prior to 7.0(3)I4(9) and 7.0(3)I7(6). Nexus 3500 Platform Switches are affected running software versions prior to 6.0(2)A8(11) and 7.0(3)I7(6). Nexus 3600 Platform Switches are affected running software versions prior to 7.0(3)F3(5). Nexus 9000 Series Switches in Standalone NX-OS Mode are affected running software versions prior to 7.0(3)I4(9), 7.0(3)I7(6). Nexus 9500 R-Series Line Cards and Fabric Modules are affected running software versions prior to 7.0(3)F3(5). Nexus 7000 and 7700 Series Switches are affected running software versions prior to 6.2(22) and 8.2(3).

A vulnerability in the management interface of Cisco Application Policy Infrastructure Controller (APIC) software could allow an unauthenticated, adjacent attacker to gain unauthorized access on an affected device. The vulnerability is due to a lack of proper access control mechanisms for IPv6 link-local connectivity imposed on the management interface of an affected device. An attacker on the same physical network could exploit this vulnerability by attempting to connect to the IPv6 link-local address on the affected device. A successful exploit could allow the attacker to bypass default access control restrictions on an affected device. Cisco Application Policy Infrastructure Controller (APIC) devices running versions prior to 4.2(0.21c) are affected.

A vulnerability in Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an authenticated, remote attacker to access sensitive information. The vulnerability occurs because the affected software does not properly validate user-supplied input. An attacker could exploit this vulnerability by issuing certain commands with filtered query results on the device. This action may cause returned messages to display confidential system information. A successful exploit could allow the attacker to read sensitive information on the device.

A vulnerability in the Trusted Platform Module (TPM) functionality of software for Cisco Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, local attacker with physical access to view sensitive information on an affected device. The vulnerability is due to a lack of proper data-protection mechanisms for disk encryption keys that are used within the partitions on an affected device hard drive. An attacker could exploit this vulnerability by obtaining physical access to the affected device to view certain cleartext keys. A successful exploit could allow the attacker to execute a custom boot process or conduct further attacks on an affected device.

A vulnerability in the SSH CLI key management functionality of Cisco NX-OS Software could allow an authenticated, local attacker to expose a user's private SSH key to all authenticated users on the targeted device. The attacker must authenticate with valid administrator device credentials. The vulnerability is due to incomplete error handling if a specific error type occurs during the SSH key export. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the CLI. A successful exploit could allow the attacker to expose a user's private SSH key. In addition, a similar type of error in the SSH key import could cause the passphrase-protected private SSH key to be imported unintentionally.

A vulnerability in the Bash shell implementation for Cisco NX-OS Software could allow an authenticated, local attacker to bypass the limited command set of the restricted Guest Shell and execute commands at the privilege level of a network-admin user outside of the Guest Shell. The attacker must authenticate with valid administrator device credentials. The vulnerability is due to the incorrect implementation of a CLI command that allows a Bash command to be incorrectly invoked on the Guest Shell CLI. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the Guest Shell prompt. A successful exploit could allow the attacker to issue commands that should be restricted by a Guest Shell account.

A vulnerability in the CLI of Cisco NX-OS Software could allow an authenticated, local attacker to execute arbitrary commands with elevated privileges on the underlying operating system of an affected device. The vulnerability is due to insufficient validation of arguments passed to certain CLI commands. 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 operating system with elevated privileges. An attacker would need valid user credentials to exploit this vulnerability.