Summary

• A vulnerability in the web management interface of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
  
  The vulnerability is due to a missing internal handler for the specific request. An attacker could exploit this vulnerability by accessing a specific hidden URL on the web management interface. A successful exploit could allow the attacker to cause a reload of the device, resulting in a 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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170405-wlc3

Affected Products

• Vulnerable Products

  This vulnerability affects only the Cisco Wireless LAN Controller 8.3.102.0 release.
  
  To determine which release of Cisco WLC Software is running on a device, administrators can use the web interface or the CLI.
  
  To use the web interface, log in to the web interface, click the Monitor tab, and then click Summary in the left pane. The Software Version field shows the release number of the software currently running on the device.
  
  To use the CLI, 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 output of the command for a device running Cisco WLC Software Release 8.3.102.0:
  
  

  (5500-4) >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

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

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:
  http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.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 upgrade 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:
  http://www.cisco.com/en/US/support/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-20170405-ame: Cisco Aironet 1830 Series and 1850 Series Access Points Mobility Express Default Credential Vulnerability
  • cisco-sa-20170405-wlc: Cisco Wireless LAN Controller 802.11 WME Denial of Service Vulnerability
  • cisco-sa-20170405-wlc2: Cisco Wireless LAN Controller IPv6 UDP Denial of Service Vulnerability
  • cisco-sa-20170405-wlc3: Cisco Wireless LAN Controller Management GUI Denial of Service Vulnerability

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

  Cisco Wireless LAN Controller Software	First Fixed Release for This Vulnerability	Recommended Release for This Vulnerability and All Vulnerabilities Described in the Collection of Advisories
  Prior to 8.0	Not vulnerable	8.0.140.0
  8.0	Not vulnerable	8.0.140.0
  8.1	Not vulnerable	8.2.141.0
  8.2	Not vulnerable	8.2.141.0
  8.3	8.3.111.0	8.3.112.0
  8.4	Not vulnerable	8.4.100.0 (future release)

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.

URL

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170405-wlc3

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	—	Final	2017-April-05

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