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Cisco Security Advisory

Cisco Wireless LAN Controller Software GUI Configuration Denial of Service Vulnerabilities

Summary

  • Multiple vulnerabilities in the administrative GUI configuration feature of Cisco Wireless LAN Controller (WLC) Software could allow an authenticated, remote attacker to cause the device to reload unexpectedly during device configuration when the administrator is using this GUI, causing a denial of service (DoS) condition on an affected device. The attacker would need to have valid administrator credentials on the device.

    These vulnerabilities are due to incomplete input validation for unexpected configuration options that the attacker could submit while accessing the GUI configuration menus. An attacker could exploit these vulnerabilities by authenticating to the device and submitting crafted user input when using the administrative GUI configuration feature. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

    These vulnerabilities have a Security Impact Rating (SIR) of High because they could be exploited when the software fix for the Cisco Wireless LAN Controller Cross-Site Request Forgery Vulnerability is not in place. In that case, an unauthenticated attacker who first exploits the cross-site request forgery vulnerability could perform arbitrary commands with the privileges of the administrator user by exploiting the vulnerabilities described in this advisory.

    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-gui

Affected Products

  • Vulnerable Products

    These vulnerabilities affect Cisco Wireless LAN Controllers that 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. As a mitigation, customers may choose to implement access control lists (ACLs) to filter or restrict management access to a configured device.

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:

    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 minor release that fixes the vulnerabilities described in this advisory and the vulnerability described in Cisco Wireless LAN Controller Cross-Site Request Forgery Vulnerability. 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 Software

    Cisco Wireless LAN Controller Major Software Release Recommended Release for These Vulnerabilities Recommended Release for All Vulnerabilities Described in the Collection of Advisories
    Prior to 8.01
    		 8.3.150.0 8.3.150.0
    8.01 8.3.150.0 8.3.150.0
    8.11 8.3.150.0 8.3.150.0
    8.21 8.3.150.0 8.3.150.0
    8.31 8.3.150.0 8.3.150.0
    8.4 8.5.140.0 8.5.140.0
    8.5 8.5.140.0 8.5.140.0
    8.6 8.8.111.0 8.8.120.0
    8.7 8.8.111.0
    		 8.8.120.0
    8.8 8.8.111.0
    		 8.8.120.0
    8.9 Not vulnerable Not vulnerable
    1. Cisco bug IDs CSCve99212 and CSCvf20684 apply only to Software Release 8.4 and later.

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.

Cisco Security Vulnerability Policy

  • To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

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Revision History

  • Version Description Section Status Date
    1.1 Corrected Fixed Software table to note recommended release 8.6, 8.7, and 8.8 as 8.8.120.0. Fixed Software Final 2019-April-18
    1.0 Initial public release. - Final 2019-April-17
    Show Less

Cisco Security Vulnerability Policy

  • To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

Subscribe to Cisco Security Notifications

Action Links for This Advisory

Related to This Advisory