Summary

• Multiple vulnerabilities in the handling of Inter-Access Point Protocol (IAPP) messages by Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition.

  The vulnerabilities exist because the software improperly validates input on fields within IAPP messages. An attacker could exploit the vulnerabilities by sending malicious IAPP messages to an affected device. A successful exploit could allow the attacker to cause the Cisco WLC Software to reload, resulting in a DoS condition.

  Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-wlc-iapp

Affected Products

• Vulnerable Products

  These vulnerabilities affect Cisco Wireless LAN Controllers (WLCs) if they are running a vulnerable software release.

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

  Determining the Cisco WLC Software Release

  To determine which Cisco WLC Software release is running on a device, administrators can use the controller web interface or the CLI.

  To use the web interface, do the following:

  1. By using a browser, log in to the controller web interface.
  2. Click the Monitor tab.
  3. Click Summary in the left pane.
  4. Under Controller Summary, the Software Version field shows the release number of the software that is currently running on the device.

  To use the CLI, log in to the controller by using Telnet, issue the show sysinfo command, and then refer to the value in the Product Version field of the command output. The following example shows the command output for a device that is running Cisco WLC Software Release 8.3.102.0:

  (wlc)> show sysinfo
  
  Manufacturer's Name.............................. Cisco Systems Inc.
  Product Name..................................... Cisco Controller
  Product Version.................................. 8.3.102.0
  Bootloader Version............................... 1.0.1
  Field Recovery Image Version..................... 6.0.182.0
  Firmware Version................................. FPGA 1.3, Env 1.6, USB console 1.27
  Build Type....................................... DATA + WPS
  .
  .
  .

  Products Confirmed Not Vulnerable

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

Workarounds

• There are no workarounds that address these vulnerabilities.

Fixed Software

• Cisco has released free software updates that address the vulnerabilities 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.

  Fixed Releases

  Customers should upgrade to an appropriate release as indicated in the table in this section. To help ensure a complete upgrade solution, consider that this advisory is part of a collection that includes the following advisories:

  • cisco-sa-20190417-aironet-shell: Cisco Aironet Series Access Points Development Shell Access Vulnerability
  • cisco-sa-20190417-wlc-csrf: Cisco Wireless LAN Controller Software Cross-Site Request Forgery Vulnerability
  • cisco-sa-20190417-wlc-gui: Cisco Wireless LAN Controller Software GUI Configuration Denial of Service Vulnerabilities
  • cisco-sa-20190417-wlc-iapp: Cisco Wireless LAN Controller Software IAPP Message Handling Denial of Service Vulnerabilities

  In the following table, the left column lists major Cisco software releases. The center column indicates whether a major release is affected by the vulnerabilities described in this advisory and the first minor release that includes the fix for these vulnerabilities. The right column indicates whether a major release is affected by all the vulnerabilities described in this collection of advisories and which release includes fixes for those vulnerabilities.

  Cisco Wireless LAN Controller Major Software Release	First Fixed Release for These Vulnerabilities	Recommended Release for All Vulnerabilities Described in the Collection of Advisories
  Prior to 8.0	8.2.170.0	8.3.150.0
  8.0	8.2.170.0	8.3.150.0
  8.1	8.2.170.0	8.3.150.0
  8.2	8.2.170.0	8.3.150.0
  8.3	8.3.150.0	8.3.150.0
  8.4	8.5.131.0	8.5.140.0
  8.5	8.5.131.0	8.5.140.0
  8.6	8.8.100.0	8.8.120.0
  8.7	8.8.100.0	8.8.120.0
  8.8	8.8.100.0	8.8.120.0
  8.9	Not vulnerable	Not vulnerable

Exploitation and Public Announcements

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

Source

• These vulnerabilities were found during internal security testing.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190417-wlc-iapp

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	-	Final	2019-April-17

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