Cisco IOS and IOS XE Software Quality of Service Remote Code Execution Vulnerability

This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS Software or Cisco IOS XE Software.

For information about which Cisco IOS and IOS XE Software releases are vulnerable, see the Fixed Software section of this advisory.

Assessing a Device

To determine whether a device that is running Cisco IOS Software or Cisco IOS XE Software may be affected by this vulnerability, administrators can log in to the device and use the show udp command in the CLI.

The device may be affected by this vulnerability if the command returns output similar to the following example:

Router> show udp

Proto  Remote   Port   Local   Port  In Out  Stat TTY OutputIF
17     0.0.0.0   0    --any--  18999  0   0    11   0

The Adaptive QoS for Dynamic Multipoint VPN (DMVPN) feature of Cisco IOS Software and Cisco IOS XE Software uses UDP port 18999 and may be open due to the provisioning of this feature on unaffected platforms. If UDP port 18999 is bound to a listening port on a device, use the Cisco IOS Software Checker to determine whether the device is running a vulnerable software release.

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
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For information about the naming and numbering conventions for Cisco IOS Software releases, see the 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
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For information about the naming and numbering conventions for Cisco IOS XE Software releases, see the Cisco IOS and NX-OS Software Reference Guide.

No other Cisco products are currently known to be affected by this vulnerability.

Cisco has confirmed that this vulnerability does not affect Cisco IOS XR Software or Cisco NX-OS Software.

from Cisco Security Advisory https://ift.tt/2pNSCvi