This vulnerability affects the following Cisco devices when running a vulnerable Cisco IOS software release and configured to accept incoming Telnet connections:
- Cisco Catalyst 2350-48TD-S Switch
- Cisco Catalyst 2350-48TD-SD Switch
- Cisco Catalyst 2360-48TD-S Switch
- Cisco Catalyst 2918-24TC-C Switch
- Cisco Catalyst 2918-24TT-C Switch
- Cisco Catalyst 2918-48TC-C Switch
- Cisco Catalyst 2918-48TT-C Switch
- Cisco Catalyst 2928-24TC-C Switch
- Cisco Catalyst 2960-24-S Switch
- Cisco Catalyst 2960-24LC-S Switch
- Cisco Catalyst 2960-24LT-L Switch
- Cisco Catalyst 2960-24PC-L Switch
- Cisco Catalyst 2960-24PC-S Switch
- Cisco Catalyst 2960-24TC-L Switch
- Cisco Catalyst 2960-24TC-S Switch
- Cisco Catalyst 2960-24TT-L Switch
- Cisco Catalyst 2960-48PST-L Switch
- Cisco Catalyst 2960-48PST-S Switch
- Cisco Catalyst 2960-48TC-L Switch
- Cisco Catalyst 2960-48TC-S Switch
- Cisco Catalyst 2960-48TT-L Switch
- Cisco Catalyst 2960-48TT-S Switch
- Cisco Catalyst 2960-8TC-L Compact Switch
- Cisco Catalyst 2960-8TC-S Compact Switch
- Cisco Catalyst 2960-Plus 24LC-L Switch
- Cisco Catalyst 2960-Plus 24LC-S Switch
- Cisco Catalyst 2960-Plus 24PC-L Switch
- Cisco Catalyst 2960-Plus 24PC-S Switch
- Cisco Catalyst 2960-Plus 24TC-L Switch
- Cisco Catalyst 2960-Plus 24TC-S Switch
- Cisco Catalyst 2960-Plus 48PST-L Switch
- Cisco Catalyst 2960-Plus 48PST-S Switch
- Cisco Catalyst 2960-Plus 48TC-L Switch
- Cisco Catalyst 2960-Plus 48TC-S Switch
- Cisco Catalyst 2960C-12PC-L Switch
- Cisco Catalyst 2960C-8PC-L Switch
- Cisco Catalyst 2960C-8TC-L Switch
- Cisco Catalyst 2960C-8TC-S Switch
- Cisco Catalyst 2960CG-8TC-L Compact Switch
- Cisco Catalyst 2960CPD-8PT-L Switch
- Cisco Catalyst 2960CPD-8TT-L Switch
- Cisco Catalyst 2960CX-8PC-L Switch
- Cisco Catalyst 2960CX-8TC-L Switch
- Cisco Catalyst 2960G-24TC-L Switch
- Cisco Catalyst 2960G-48TC-L Switch
- Cisco Catalyst 2960G-8TC-L Compact Switch
- Cisco Catalyst 2960L-16PS-LL Switch
- Cisco Catalyst 2960L-16TS-LL Switch
- Cisco Catalyst 2960L-24PS-LL Switch
- Cisco Catalyst 2960L-24TS-LL Switch
- Cisco Catalyst 2960L-48PS-LL Switch
- Cisco Catalyst 2960L-48TS-LL Switch
- Cisco Catalyst 2960L-8PS-LL Switch
- Cisco Catalyst 2960L-8TS-LL Switch
- Cisco Catalyst 2960PD-8TT-L Compact Switch
- Cisco Catalyst 2960S-24PD-L Switch
- Cisco Catalyst 2960S-24PS-L Switch
- Cisco Catalyst 2960S-24TD-L Switch
- Cisco Catalyst 2960S-24TS-L Switch
- Cisco Catalyst 2960S-24TS-S Switch
- Cisco Catalyst 2960S-48FPD-L Switch
- Cisco Catalyst 2960S-48FPS-L Switch
- Cisco Catalyst 2960S-48LPD-L Switch
- Cisco Catalyst 2960S-48LPS-L Switch
- Cisco Catalyst 2960S-48TD-L Switch
- Cisco Catalyst 2960S-48TS-L Switch
- Cisco Catalyst 2960S-48TS-S Switch
- Cisco Catalyst 2960S-F24PS-L Switch
- Cisco Catalyst 2960S-F24TS-L Switch
- Cisco Catalyst 2960S-F24TS-S Switch
- Cisco Catalyst 2960S-F48FPS-L Switch
- Cisco Catalyst 2960S-F48LPS-L Switch
- Cisco Catalyst 2960S-F48TS-L Switch
- Cisco Catalyst 2960S-F48TS-S Switch
- Cisco Catalyst 2960X-24PD-L Switch
- Cisco Catalyst 2960X-24PS-L Switch
- Cisco Catalyst 2960X-24PSQ-L Cool Switch
- Cisco Catalyst 2960X-24TD-L Switch
- Cisco Catalyst 2960X-24TS-L Switch
- Cisco Catalyst 2960X-24TS-LL Switch
- Cisco Catalyst 2960X-48FPD-L Switch
- Cisco Catalyst 2960X-48FPS-L Switch
- Cisco Catalyst 2960X-48LPD-L Switch
- Cisco Catalyst 2960X-48LPS-L Switch
- Cisco Catalyst 2960X-48TD-L Switch
- Cisco Catalyst 2960X-48TS-L Switch
- Cisco Catalyst 2960X-48TS-LL Switch
- Cisco Catalyst 2960XR-24PD-I Switch
- Cisco Catalyst 2960XR-24PD-L Switch
- Cisco Catalyst 2960XR-24PS-I Switch
- Cisco Catalyst 2960XR-24PS-L Switch
- Cisco Catalyst 2960XR-24TD-I Switch
- Cisco Catalyst 2960XR-24TD-L Switch
- Cisco Catalyst 2960XR-24TS-I Switch
- Cisco Catalyst 2960XR-24TS-L Switch
- Cisco Catalyst 2960XR-48FPD-I Switch
- Cisco Catalyst 2960XR-48FPD-L Switch
- Cisco Catalyst 2960XR-48FPS-I Switch
- Cisco Catalyst 2960XR-48FPS-L Switch
- Cisco Catalyst 2960XR-48LPD-I Switch
- Cisco Catalyst 2960XR-48LPD-L Switch
- Cisco Catalyst 2960XR-48LPS-I Switch
- Cisco Catalyst 2960XR-48LPS-L Switch
- Cisco Catalyst 2960XR-48TD-I Switch
- Cisco Catalyst 2960XR-48TD-L Switch
- Cisco Catalyst 2960XR-48TS-I Switch
- Cisco Catalyst 2960XR-48TS-L Switch
- Cisco Catalyst 2970G-24T Switch
- Cisco Catalyst 2970G-24TS Switch
- Cisco Catalyst 2975 Switch
- Cisco Catalyst 3550 12G Switch
- Cisco Catalyst 3550 12T Switch
- Cisco Catalyst 3550 24 DC SMI Switch
- Cisco Catalyst 3550 24 EMI Switch
- Cisco Catalyst 3550 24 FX SMI Switch
- Cisco Catalyst 3550 24 PWR Switch
- Cisco Catalyst 3550 24 SMI Switch
- Cisco Catalyst 3550 48 EMI Switch
- Cisco Catalyst 3550 48 SMI Switch
- Cisco Catalyst 3560-12PC-S Compact Switch
- Cisco Catalyst 3560-24PS Switch
- Cisco Catalyst 3560-24TS Switch
- Cisco Catalyst 3560-48PS Switch
- Cisco Catalyst 3560-48TS Switch
- Cisco Catalyst 3560-8PC Compact Switch
- Cisco Catalyst 3560C-12PC-S Switch
- Cisco Catalyst 3560C-8PC-S Switch
- Cisco Catalyst 3560CG-8PC-S Compact Switch
- Cisco Catalyst 3560CG-8TC-S Compact Switch
- Cisco Catalyst 3560CPD-8PT-S Compact Switch
- Cisco Catalyst 3560CX-12PC-S Switch
- Cisco Catalyst 3560CX-12PD-S Switch
- Cisco Catalyst 3560CX-12TC-S Switch
- Cisco Catalyst 3560CX-8PC-S Switch
- Cisco Catalyst 3560CX-8PT-S Switch
- Cisco Catalyst 3560CX-8TC-S Switch
- Cisco Catalyst 3560CX-8XPD-S Switch
- Cisco Catalyst 3560E-12D-E Switch
- Cisco Catalyst 3560E-12D-S Switch
- Cisco Catalyst 3560E-12SD-E Switch
- Cisco Catalyst 3560E-12SD-S Switch
- Cisco Catalyst 3560E-24PD-E Switch
- Cisco Catalyst 3560E-24PD-S Switch
- Cisco Catalyst 3560E-24TD-E Switch
- Cisco Catalyst 3560E-24TD-S Switch
- Cisco Catalyst 3560E-48PD-E Switch
- Cisco Catalyst 3560E-48PD-EF Switch
- Cisco Catalyst 3560E-48PD-S Switch
- Cisco Catalyst 3560E-48PD-SF Switch
- Cisco Catalyst 3560E-48TD-E Switch
- Cisco Catalyst 3560E-48TD-S Switch
- Cisco Catalyst 3560G-24PS Switch
- Cisco Catalyst 3560G-24TS Switch
- Cisco Catalyst 3560G-48PS Switch
- Cisco Catalyst 3560G-48TS Switch
- Cisco Catalyst 3560V2-24DC Switch
- Cisco Catalyst 3560V2-24PS Switch
- Cisco Catalyst 3560V2-24TS Switch
- Cisco Catalyst 3560V2-48PS Switch
- Cisco Catalyst 3560V2-48TS Switch
- Cisco Catalyst 3560X-24P-E Switch
- Cisco Catalyst 3560X-24P-L Switch
- Cisco Catalyst 3560X-24P-S Switch
- Cisco Catalyst 3560X-24T-E Switch
- Cisco Catalyst 3560X-24T-L Switch
- Cisco Catalyst 3560X-24T-S Switch
- Cisco Catalyst 3560X-24U-E Switch
- Cisco Catalyst 3560X-24U-L Switch
- Cisco Catalyst 3560X-24U-S Switch
- Cisco Catalyst 3560X-48P-E Switch
- Cisco Catalyst 3560X-48P-L Switch
- Cisco Catalyst 3560X-48P-S Switch
- Cisco Catalyst 3560X-48PF-E Switch
- Cisco Catalyst 3560X-48PF-L Switch
- Cisco Catalyst 3560X-48PF-S Switch
- Cisco Catalyst 3560X-48T-E Switch
- Cisco Catalyst 3560X-48T-L Switch
- Cisco Catalyst 3560X-48T-S Switch
- Cisco Catalyst 3560X-48U-E Switch
- Cisco Catalyst 3560X-48U-L Switch
- Cisco Catalyst 3560X-48U-S Switch
- Cisco Catalyst 3750 Metro 24-AC Switch
- Cisco Catalyst 3750 Metro 24-DC Switch
- Cisco Catalyst 3750-24FS Switch
- Cisco Catalyst 3750-24PS Switch
- Cisco Catalyst 3750-24TS Switch
- Cisco Catalyst 3750-48PS Switch
- Cisco Catalyst 3750-48TS Switch
- Cisco Catalyst 3750E-24PD-E Switch
- Cisco Catalyst 3750E-24PD-S Switch
- Cisco Catalyst 3750E-24TD-E Switch
- Cisco Catalyst 3750E-24TD-S Switch
- Cisco Catalyst 3750E-48PD-E Switch
- Cisco Catalyst 3750E-48PD-EF Switch
- Cisco Catalyst 3750E-48PD-S Switch
- Cisco Catalyst 3750E-48PD-SF Switch
- Cisco Catalyst 3750E-48TD-E Switch
- Cisco Catalyst 3750E-48TD-S Switch
- Cisco Catalyst 3750G-12S Switch
- Cisco Catalyst 3750G-12S-SD Switch
- Cisco Catalyst 3750G-16TD Switch
- Cisco Catalyst 3750G-24PS Switch
- Cisco Catalyst 3750G-24T Switch
- Cisco Catalyst 3750G-24TS Switch
- Cisco Catalyst 3750G-24TS-1U Switch
- Cisco Catalyst 3750G-48PS Switch
- Cisco Catalyst 3750G-48TS Switch
- Cisco Catalyst 3750V2-24FS Switch
- Cisco Catalyst 3750V2-24PS Switch
- Cisco Catalyst 3750V2-24TS Switch
- Cisco Catalyst 3750V2-48PS Switch
- Cisco Catalyst 3750V2-48TS Switch
- Cisco Catalyst 3750X-12S-E Switch
- Cisco Catalyst 3750X-12S-S Switch
- Cisco Catalyst 3750X-24P-E Switch
- Cisco Catalyst 3750X-24P-L Switch
- Cisco Catalyst 3750X-24P-S Switch
- Cisco Catalyst 3750X-24S-E Switch
- Cisco Catalyst 3750X-24S-S Switch
- Cisco Catalyst 3750X-24T-E Switch
- Cisco Catalyst 3750X-24T-L Switch
- Cisco Catalyst 3750X-24T-S Switch
- Cisco Catalyst 3750X-24U-E Switch
- Cisco Catalyst 3750X-24U-L Switch
- Cisco Catalyst 3750X-24U-S Switch
- Cisco Catalyst 3750X-48P-E Switch
- Cisco Catalyst 3750X-48P-L Switch
- Cisco Catalyst 3750X-48P-S Switch
- Cisco Catalyst 3750X-48PF-E Switch
- Cisco Catalyst 3750X-48PF-L Switch
- Cisco Catalyst 3750X-48PF-S Switch
- Cisco Catalyst 3750X-48T-E Switch
- Cisco Catalyst 3750X-48T-L Switch
- Cisco Catalyst 3750X-48T-S Switch
- Cisco Catalyst 3750X-48U-E Switch
- Cisco Catalyst 3750X-48U-L Switch
- Cisco Catalyst 3750X-48U-S Switch
- Cisco Catalyst 4000 Supervisor Engine I
- Cisco Catalyst 4000/4500 Supervisor Engine IV
- Cisco Catalyst 4000/4500 Supervisor Engine V
- Cisco Catalyst 4500 Series Supervisor Engine II-Plus
- Cisco Catalyst 4500 Series Supervisor Engine II-Plus-TS
- Cisco Catalyst 4500 Series Supervisor Engine V-10GE
- Cisco Catalyst 4500 Series Supervisor II-Plus-10GE
- Cisco Catalyst 4500 Supervisor Engine 6-E
- Cisco Catalyst 4500 Supervisor Engine 6L-E
- Cisco Catalyst 4500E Supervisor Engine 8-E
- Cisco Catalyst 4900M Switch
- Cisco Catalyst 4928 10 Gigabit Ethernet Switch
- Cisco Catalyst 4948 10 Gigabit Ethernet Switch
- Cisco Catalyst 4948 Switch
- Cisco Catalyst 4948E Ethernet Switch
- Cisco Catalyst 4948E-F Ethernet Switch
- Cisco Catalyst Blade Switch 3020 for HP
- Cisco Catalyst Blade Switch 3030 for Dell
- Cisco Catalyst Blade Switch 3032 for Dell M1000E
- Cisco Catalyst Blade Switch 3040 for FSC
- Cisco Catalyst Blade Switch 3120 for HP
- Cisco Catalyst Blade Switch 3120X for HP
- Cisco Catalyst Blade Switch 3130 for Dell M1000E
- Cisco Catalyst C2928-24LT-C Switch
- Cisco Catalyst C2928-48TC-C Switch
- Cisco Catalyst Switch Module 3012 for IBM BladeCenter
- Cisco Catalyst Switch Module 3110 for IBM BladeCenter
- Cisco Catalyst Switch Module 3110X for IBM BladeCenter
- Cisco Embedded Service 2020 24TC CON B Switch
- Cisco Embedded Service 2020 24TC CON Switch
- Cisco Embedded Service 2020 24TC NCP B Switch
- Cisco Embedded Service 2020 24TC NCP Switch
- Cisco Embedded Service 2020 CON B Switch
- Cisco Embedded Service 2020 CON Switch
- Cisco Embedded Service 2020 NCP B Switch
- Cisco Embedded Service 2020 NCP Switch
- Cisco Enhanced Layer 2 EtherSwitch Service Module
- Cisco Enhanced Layer 2/3 EtherSwitch Service Module
- Cisco Gigabit Ethernet Switch Module (CGESM) for HP
- Cisco IE 2000-16PTC-G Industrial Ethernet Switch
- Cisco IE 2000-16T67 Industrial Ethernet Switch
- Cisco IE 2000-16T67P Industrial Ethernet Switch
- Cisco IE 2000-16TC Industrial Ethernet Switch
- Cisco IE 2000-16TC-G Industrial Ethernet Switch
- Cisco IE 2000-16TC-G-E Industrial Ethernet Switch
- Cisco IE 2000-16TC-G-N Industrial Ethernet Switch
- Cisco IE 2000-16TC-G-X Industrial Ethernet Switch
- Cisco IE 2000-24T67 Industrial Ethernet Switch
- Cisco IE 2000-4S-TS-G Industrial Ethernet Switch
- Cisco IE 2000-4T Industrial Ethernet Switch
- Cisco IE 2000-4T-G Industrial Ethernet Switch
- Cisco IE 2000-4TS Industrial Ethernet Switch
- Cisco IE 2000-4TS-G Industrial Ethernet Switch
- Cisco IE 2000-8T67 Industrial Ethernet Switch
- Cisco IE 2000-8T67P Industrial Ethernet Switch
- Cisco IE 2000-8TC Industrial Ethernet Switch
- Cisco IE 2000-8TC-G Industrial Ethernet Switch
- Cisco IE 2000-8TC-G-E Industrial Ethernet Switch
- Cisco IE 2000-8TC-G-N Industrial Ethernet Switch
- Cisco IE 3000-4TC Industrial Ethernet Switch
- Cisco IE 3000-8TC Industrial Ethernet Switch
- Cisco IE-3010-16S-8PC Industrial Ethernet Switch
- Cisco IE-3010-24TC Industrial Ethernet Switch
- Cisco IE-4000-16GT4G-E Industrial Ethernet Switch
- Cisco IE-4000-16T4G-E Industrial Ethernet Switch
- Cisco IE-4000-4GC4GP4G-E Industrial Ethernet Switch
- Cisco IE-4000-4GS8GP4G-E Industrial Ethernet Switch
- Cisco IE-4000-4S8P4G-E Industrial Ethernet Switch
- Cisco IE-4000-4T4P4G-E Industrial Ethernet Switch
- Cisco IE-4000-4TC4G-E Industrial Ethernet Switch
- Cisco IE-4000-8GS4G-E Industrial Ethernet Switch
- Cisco IE-4000-8GT4G-E Industrial Ethernet Switch
- Cisco IE-4000-8GT8GP4G-E Industrial Ethernet Switch
- Cisco IE-4000-8S4G-E Industrial Ethernet Switch
- Cisco IE-4000-8T4G-E Industrial Ethernet Switch
- Cisco IE-4010-16S12P Industrial Ethernet Switch
- Cisco IE-4010-4S24P Industrial Ethernet Switch
- Cisco IE-5000-12S12P-10G Industrial Ethernet Switch
- Cisco IE-5000-16S12P Industrial Ethernet Switch
- Cisco ME 4924-10GE Switch
- Cisco RF Gateway 10
- Cisco SM-X Layer 2/3 EtherSwitch Service Module
Note: Checking for the presence of the CMP subsystem is only required on devices running Cisco IOS XE Software, not Cisco IOS Software. Checking if the device is configured to accept Telnet connections is required for devices running either Cisco IOS or Cisco IOS XE Software.
Cisco devices running a vulnerable Cisco IOS XE release are affected by this vulnerability when the following conditions are met:
- The CMP subsystem is present on the Cisco IOS XE software image running on the device, and
- The device is configured to accept incoming Telnet connections.
In order to determine if the CMP subsystem is present on the running software image, execute the command
show subsys class protocol | include ^cmp from a privileged CLI prompt on the device.
The following example shows the output of the command
show subsys class protocol | include ^cmp when the CMP subsystem is present on the software image running on the device:
Switch#show subsys class protocol | include ^cmp
cmp Protocol 1.000.001
Switch#
The following example shows the output of the command
show subsys class protocol | include ^cmp when the CMP subsystem is
not present on the software image running on the device:
Switch#show subsys class protocol | include ^cmp
Switch#
In order to determine if the device is configured to accept incoming Telnet connections, execute the command
show running-config | include ^line vty|transport input from a privileged CLI prompt. The command output may indicate one of multiple possible configurations, such as the following:
- The absence of a transport input configuration line after the line vty configuration line indicates the device is using the default set of protocols for incoming connections through a virtual terminal (VTY). The default set of protocols includes the Telnet protocol; hence, this device will accept Telnet connections on all VTYs. This is a vulnerable configuration.
Switch#show running-config | include ^line vty|transport input
line vty 0 4
line vty 5 15
Switch#
- The device has been explicitly configured to only accept the Secure Shell (SSH) protocol for incoming connections to a subset of the available VTYs, but VTYs numbered 6 to 15 are still using the default set of protocols. Hence, this device will accept Telnet connections to those VTYs. This is a vulnerable configuration.
Switch#show running-config | include ^line vty|transport input
line vty 0 4
transport input ssh
line vty 5
transport input ssh
line vty 6 15
Switch#
- All available transport protocols have been enabled for incoming connections to all VTYs. Enabling all protocols also enables the Telnet protocol, and will allow Telnet connections to the device. This is a vulnerable configuration.
Switch#show running-config | include ^line vty|transport input
line vty 0 4
transport input all
line vty 5 15
transport input all
Switch#
- The SSH protocol is the only protocol enabled for incoming connections on all VTYs. No Telnet connections are possible to any VTY on the device while using this configuration. This configuration is not vulnerable.
Switch#show running-config | include ^line vty|transport input
line vty 0 4
transport input ssh
line vty 5 15
transport input ssh
Switch#
-
Both the Telnet and the SSH protocols have been explicitly enabled as allowed protocols for incoming connections on all VTYs. Telnet connections to the device will be successful under this configuration. This is a vulnerable configuration.
Switch#show running-config | include ^line vty|transport input
line vty 0 4
transport input telnet ssh
line vty 5 15
transport input telnet ssh
Determining the Cisco IOS Software Release
To determine which Cisco IOS Software release is running on a device, administrators can log in to the device, use the show version command in the CLI, and then refer to the system banner that appears. If the device is running Cisco IOS Software, the system banner displays text similar to Cisco Internetwork Operating System Software or Cisco IOS Software. The banner also displays the installed image name in parentheses, followed by the Cisco IOS Software release number and release name. Some Cisco devices do not support the show version command or may provide different output.
The following example shows the output of the command for a device that is running Cisco IOS Software Release 15.5(2)T1 and has an installed image name of C2951-UNIVERSALK9-M:
Router> show version
Cisco IOS Software, C2951 Software (C2951-UNIVERSALK9-M), Version 15.5(2)T1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2015 by Cisco Systems, Inc.
Compiled Mon 22-Jun-15 09:32 by prod_rel_team
.
.
.
For information about the naming and numbering conventions for Cisco IOS Software releases, see White Paper: Cisco IOS and NX-OS Software Reference Guide.
Determining the Cisco IOS XE Software Release
To determine which Cisco IOS XE Software release is running on a device, administrators can log in to the device, use the show version command in the CLI, and then refer to the system banner that appears. If the device is running Cisco IOS XE Software, the system banner displays Cisco IOS Software, Cisco IOS XE Software, or similar text.
The following example shows the output of the command for a device that is running Cisco IOS XE Software Release 16.2.1 and has an installed image name of CAT3K_CAA-UNIVERSALK9-M:
ios-xe-device# show version
Cisco IOS Software, Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version Denali 16.2.1, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2016 by Cisco Systems, Inc.
Compiled Sun 27-Mar-16 21:47 by mcpre
.
.
.
For information about the naming and numbering conventions for Cisco IOS XE Software releases, see White Paper: Cisco IOS and NX-OS Software Reference Guide.
No other Cisco products are currently known to be affected by this vulnerability.
Cisco devices running a vulnerable Cisco IOS Software release but not listed under the "Vulnerable Products" section of this advisory are not affected by this vulnerability.
Cisco devices running a vulnerable Cisco IOS XE Software release but not including the CMP protocol subsystem are not affected by this vulnerability.