Summary

• A vulnerability in the implementation of the Low Power, Wide Area (LPWA) subsystem of Cisco IOS Software for Cisco 800 Series Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an unauthenticated, remote attacker to gain unauthorized read access to sensitive data or cause a denial of service (DoS) condition.

  The vulnerability is due to a lack of input and validation checking mechanisms for virtual-LPWA (VLPWA) protocol modem messages. An attacker could exploit this vulnerability by supplying crafted packets to an affected device. A successful exploit could allow the attacker to gain unauthorized read access to sensitive data or cause the VLPWA interface of the affected device to shut down, resulting in DoS condition.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-lpwa-access-cXsD7PRA

  This advisory is part of the September 24, 2020, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 25 Cisco Security Advisories that describe 34 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: September 2020 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.

Affected Products

• Vulnerable Products

  This vulnerability affects the following Cisco products if they are running a vulnerable release of Cisco IOS Software and have a VLPWA interface enabled:

  • 807 Industrial ISRs
  • 809 Industrial ISRs
  • 829 Industrial ISRs
  • CGR1000 Routers

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

  Determine Whether a VLPWA Interface Is Enabled

  To determine whether a VLPWA interface is enabled, use the show control-plane host open-ports EXEC command in the CLI. If TCP port 5888 is open on a device, a VLPWA interface is enabled and the device is processing VLPWA protocol modem messages.

  The following example shows the output of the show control-plane host open-ports command on a device that has a VLPWA interface enabled and that is processing VLPWA protocol modem messages using either IP Version 4 (IPv4) or IP Version 6 (IPv6) for port TCP 5888.

  Router#show control-plane host open-ports 
  Active internet connections (servers and established)
  Prot   Local Address  Foreign Address    Service     State
  tcp     *:5888             *:0          VLPWA Proc   LISTEN
  
  

  
  

  Products Confirmed Not Vulnerable

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.

  Cisco has confirmed that this vulnerability does not affect the following Cisco products:

  • 800 Series Integrated Services Routers
  • 2000 Series Connected Grid Routers
  • IOS XE Software
  • IOS XR Software
  • NX-OS Software

Details

• A VLPWA interface can be enabled on Cisco ISRs and Connected Grid Routers to configure and monitor the status of a Cisco Wireless Gateway for LoRaWAN, which is a module from the Cisco Internet of Things (IoT) extension module series that is used to provide LPWA access to the connected devices.

  If the VLPWA interface of an affected device is configured with the lpwa modem authentication mandatory enable feature, exploitation of this vulnerability would cause the interface to shut down. Otherwise, if the VLPWA interface is not configured with the lpwa modem authentication mandatory enable feature, successful exploitation could allow the attacker to gain unauthorized access to sensitive data that is stored on the device.

  The following example shows the output of the show running-config interface virtual lpwa 1| include authentication mandatory enable command for a device that has the VLPWA interface 1 with the lpwa modem authentication mandatory enable feature enabled:

  Router# show running-config interface virtual-lpwa 1| include authentication mandatory enable 
   lpwa modem authentication mandatory enable

  Exploitation of this vulnerability does not require a Cisco Wireless Gateway for LoRaWAN module to be connected to an affected device.

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• Cisco has released free software updates that address the vulnerability described in this advisory. Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:
  https://www.cisco.com/c/en/us/products/end-user-license-agreement.html

  Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.

  When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Customers Without Service Contracts

  Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC: https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html

  Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.

  Cisco IOS and IOS XE Software

  To help customers determine their exposure to vulnerabilities in Cisco IOS and IOS XE Software, Cisco provides the Cisco Software Checker to identify any Cisco Security Advisories that impact a specific software release and the earliest release that fixes the vulnerabilities described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities described in all the advisories identified (“Combined First Fixed”).

  Customers can use the Cisco Software Checker to search advisories in the following ways:

  • Choose the software and one or more releases
  • Upload a .txt file that includes a list of specific releases
  • Enter the output of the show version command

  After initiating a search, customers can customize the search to include all Cisco Security Advisories, a specific advisory, or all advisories in the most recent bundled publication.

  Customers can also use the following form to determine whether a release is affected by any Cisco Security Advisory by entering a Cisco IOS or IOS XE Software release-for example, 15.1(4)M2 or 3.13.8S:

  By default, the Cisco Software Checker includes results only for vulnerabilities that have a Critical or High Security Impact Rating (SIR). To include results for Medium SIR vulnerabilities, customers can use the Cisco Software Checker on Cisco.com and check the Medium check box in the drop-down list under Impact Rating when customizing a search.

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

• This vulnerability was found by X.B. of the Cisco Advanced Security Initiatives Group (ASIG) during internal security testing.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-lpwa-access-cXsD7PRA

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2020-SEP-24

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