Summary

• A vulnerability in the virtual console authentication of Cisco IOS Software for Cisco 809 and 829 Industrial Integrated Services Routers (Industrial ISRs) and Cisco 1000 Series Connected Grid Routers (CGR1000) could allow an authenticated but low-privileged, local attacker to log in to the Virtual Device Server (VDS) of an affected device by using a set of default credentials.

  The vulnerability is due to the presence of weak, hard-coded credentials. An attacker could exploit this vulnerability by authenticating to the targeted device and then connecting to VDS through the device’s virtual console by using the static credentials. A successful exploit could allow the attacker to access the Linux shell of VDS as the root user.

  Cisco has released software updates that address this vulnerability. There is a workaround that addresses this vulnerability in Cisco IOS Software releases 15.6(3)M and later.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-iot-vds-cred-uPMp9zbY

  This advisory is part of the June 3, 2020, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 23 Cisco Security Advisories that describe 25 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: June 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:

  • Cisco 809 and 829 Industrial ISRs
  • CGR1000

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

  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 ISRs
  • 807 Industrial ISRs
  • IOS XE Software
  • IOS XR Software
  • NX-OS Software

Details

• Cisco 800 Series Industrial ISRs and Cisco CGR1000 devices are designed on a hypervisor architecture, where Cisco IOS Software, a Guest Operating System (Guest OS), and VDS run as separate virtual machines (VMs). Cisco IOS Software and Guest OS need to access some shared devices. Examples are embedded multimedia card eMMC flash memory, USB ports, and the console. VDS coordinates access to the shared devices and provides communication channels between VMs over emulated Ethernet interfaces.

  The vulnerability described in this advisory is localized in the context of VDS; under no circumstances could an attacker use the static credentials to log in to the Cisco IOS Software VM.

Workarounds

• There is a workaround that addresses this vulnerability in Cisco IOS Software releases 15.6(3)M and later.

  These releases introduced the global configuration command iox hypervisor password <strong_password> to allow administrators to replace the default password that is used to log in to VDS. An administrator can use this command to define a strong password to replace the default password that provides VDS access on an affected device, as shown in the following example:

  Router#configure terminal
  router(config)#iox hypervisor password 
  Router(config)#end
  Router#

  This action may be a suitable workaround until switches that are affected by this vulnerability can be upgraded.

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 and Alerts 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 Software

  To help customers determine their exposure to vulnerabilities in Cisco IOS Software, Cisco provides the Cisco Software Checker to identify any Cisco Security Advisories that impact a specific Cisco IOS 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 use the following form to determine whether a release is affected by any Cisco Security Advisory by entering a Cisco IOS Software release-for example, 15.1(4)M2:

  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.

  Fixed Releases for All VDS-Related Vulnerabilities in This Bundle of Advisories

  This release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication contains multiple advisories for vulnerabilities that affect VDS. To help ensure a complete upgrade solution for these vulnerabilities, administrators are advised to upgrade affected devices to a fixed software release that addresses all VDS-related advisories in this bundled publication:

  • cisco-sa-ios-iot-udp-vds-inj-f2D5Jzrt
  • cisco-sa-ios-iot-vds-cmd-inj-VfJtqGhE
  • cisco-sa-ios-iot-vds-cred-uPMp9zbY
  • cisco-sa-ios-ir800-img-verif-wHhLYHjK

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 during internal security testing by X.B. of the Cisco Advanced Security Initiatives Group (ASIG) and E.I. of Cisco PSIRT.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-iot-vds-cred-uPMp9zbY

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2020-JUN-03

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