Summary

• A vulnerability in the Cisco Nexus 9000 Series Fabric Switches running in Application-Centric Infrastructure (ACI) mode could allow an authenticated, local attacker to read arbitrary files on an affected device.

  The vulnerability is due to a lack of proper input and validation checking mechanisms of user-supplied input sent to an affected device. A successful exploit could allow the attacker unauthorized access to read arbitrary files on an affected device.

  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-20190306-aci-file-read

Affected Products

• Vulnerable Products

  This vulnerability affects Cisco Nexus 9000 Series Fabric Switches in ACI mode when they are running an affected release of Cisco NX-OS Software.

  For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory.

  Determining the Cisco NX-OS Software Release

  Administrators can determine the release of Cisco NX-OS Software running on a device by using the show version command in the device CLI. The following example identifies the 11.2(2) Release:

  nxos-n9k-aci# show version
  Cisco Nexus Operating System (NX-OS) Software
  such license is available at
  http://www.opensource.org/licenses/gpl-2.0.php and http://www.opensource.org/licenses/lgpl-2.1.php
  Software
  BIOS:      version N/A
  kickstart: version 11.2(2) [build 11.2(1.184)]
  system:    version 11.2(2) [build 11.2(1.184)]
  .
  .
  .

  Determining the Cisco Application Policy Infrastructure Controller Software Release

  There is a one-to-one mapping between the software for Cisco Application Policy Infrastructure Controller (APIC) and Cisco Nexus 9000 Series Fabric Switches in ACI mode. To determine which Cisco APIC Software release is running on a device, administrators can disregard the leftmost digit of the Cisco NX-OS Software version number. In the preceding example, the output shows Cisco NX-OS Software version 11.2(2), which maps to Cisco APIC Software Release 1.2(2).

  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 determined that this vulnerability does not affect the following Cisco products:

  • Firepower 2100 Series
  • Firepower 4100 Series
  • Firepower 9300 Security Appliances
  • MDS 9000 Series Multilayer Switches
  • Nexus 1000V Switch for Microsoft Hyper-V
  • Nexus 1000V Switch for VMware vSphere
  • Nexus 2000 Series Fabric Extenders
  • Nexus 3000 Series Switches
  • Nexus 3500 Platform Switches
  • Nexus 3600 Platform Switches
  • Nexus 5000 Series Switches
  • Nexus 5500 Platform Switches
  • Nexus 5600 Platform Switches
  • Nexus 7000 Series Switches
  • Nexus 7700 Series Switches
  • Nexus 9000 Series Switches in standalone NX-OS mode
  • Nexus 9500 R-Series Switching Platform
  • UCS 6200 Series Fabric Interconnects
  • UCS 6300 Series Fabric Interconnects
  • UCS 6400 Series Fabric Interconnects

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• For information about fixed software releases, consult the Cisco bug ID(s) at the top of this advisory.

  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.

  Additional Resources

  For help determining the best Cisco NX-OS Software release for a Cisco Nexus Switch, administrators can refer to the following Recommended Releases documents. If a security advisory recommends a later release, Cisco recommends following the advisory guidance.

  Cisco MDS Series Switches
  Cisco Nexus 1000V for VMware Switch
  Cisco Nexus 3000 Series and 3500 Series Switches
  Cisco Nexus 5000 Series Switches
  Cisco Nexus 5500 Platform Switches
  Cisco Nexus 6000 Series Switches
  Cisco Nexus 7000 Series Switches
  Cisco Nexus 9000 Series Switches
  Cisco Nexus 9000 Series ACI-Mode Switches

  For help determining the best Cisco NX-OS Software release for Cisco UCS, refer to the Recommended Releases documents in the release notes for the device.

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

• Cisco would like to thank Nicolas Biscos and Gaëtan Ferry from Synacktiv for reporting this vulnerability.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190306-aci-file-read

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2019-March-06

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