Summary

• Multiple vulnerabilities exist in the Cisco Wireless LAN Controller (WLC) platforms. This security advisory outlines the details of the following vulnerabilities:

  • Malformed HTTP or HTTPS authentication response denial of service vulnerability
    
  • SSH connections denial of service vulnerability
    
  • Crafted HTTP or HTTPS request denial of service vulnerability
    
  • Crafted HTTP or HTTPS request unauthorized configuration modification vulnerability
    

  Cisco has released software updates that address these vulnerabilities.

  This advisory is posted at: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20090727-wlc

Affected Products

• Vulnerable Products

  Cisco 1500 Series, 2000 Series, 2100 Series, 4400 Series, 4100 Series, 4200 Series, Wireless Services Modules (WiSM), WLC Modules for Integrated Services Routers, and Cisco Catalyst 3750G Integrated Wireless LAN Controllers are affected by one or more of the following vulnerabilities:

  • The malformed HTTP or HTTPS authentication response denial of service vulnerability affects software versions 3.2 and later.
    
  • The SSH connections denial of service vulnerability affects software versions 3.2 and later.
    
  • The crafted HTTP or HTTPS request denial of service vulnerability affects software versions 4.1 and later.
    
  • The crafted HTTP or HTTPS request unauthorized configuration modification vulnerability affects software versions 3.2 and later.
    

  Determination of Software Versions

  To determine the WLC version that is running in a given environment, use one of the following methods:

  • In the web interface, choose the Monitor tab, click Summary in the left pane, and note the Software Version field.
    

    Note: Customers who use a WLC Module in an Integrated Services Router (ISR) will need to issue the service-module wlan-controller 1/0 session command prior to performing the next step on the command line. Customers who use a Cisco Catalyst 3750G Switch with an integrated WLC Module will need to issue the session processor 1 session command prior to performing the next step on the command line.

  • From the command-line interface, type show sysinfo and note the Product Version field, as shown in the following example:
    

  (Cisco Controller) >show sysinfo 
  
  Manufacturer's Name.. Cisco Systems Inc.
  Product Name......... Cisco Controller
  Product Version...... 5.1.151.0
  RTOS Version......... Linux-2.6.10_mvl401
  Bootloader Version... 4.0.207.0
  Build Type........... DATA + WPS
  

  Use the show wism module controller 1 status command on a Cisco Catalyst 6500 Series/7600 Series Switch if you are using a WiSM. Note the software version as demonstrated in the following example, which shows version 5.1.151.0.

  Router#show wism module 3 controller 1 status
  
  WiSM Controller 1 in Slot 3
  Operational Status of the Controller    
     : Oper-Up
  Service VLAN                            
     : 192   
  Service Port                            
     : 10    
  Service Port Mac Address                
     : 0011.92ff.8742
  Service IP Address                      
     : 192.168.10.1
  Management IP Address                   
     : 192.168.1.123
  Software Version                        
     : 5.1.151.0
  Port Channel Number                     
     : 288   
  Allowed vlan list                       
     : 30,40 
  Native VLAN ID                          
     : 40    
  WCP Keep Alive Missed                   
     : 0

  Products Confirmed Not Vulnerable

  The Cisco Wireless Controller 5500 Series is not affected by these vulnerabilities.

Details

• Cisco Wireless LAN Controllers (WLCs) are responsible for system-wide wireless LAN functions, such as security policies, intrusion prevention, RF management, quality of service (QoS), and mobility.

  These devices communicate with controller-based access points over any Layer 2 (Ethernet) or Layer 3 (IP) infrastructure using the Lightweight Access Point Protocol (LWAPP).

  This security advisory describes multiple distinct vulnerabilities in the WLC family of devices.

  • Malformed HTTP or HTTPS authentication response denial of service vulnerability
    An attacker with access to the administrative web interface via HTTP or HTTPS may cause the device to reload by providing a malformed response to an authentication request.
    

    Note: The vulnerability can be exploited only via the administrative web-based interface; Web Authentication features are not affected.

    
    This vulnerability is documented in Cisco Bug ID CSCsx03715 ( registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2009-1164.
    
  • SSH connections denial of service vulnerability
    Affected devices may be susceptible to a memory leak when they handle SSH management connections. An attacker could use this behavior to cause an affected device to crash and reload.
    

    Note: A three-way handshake is not required to exploit this vulnerability.

    
    This vulnerability is documented in Cisco Bug ID CSCsw40789 ( registered customers only) and has been assigned CVE ID CVE-2009-1165.
    
  • Crafted HTTP or HTTPS request denial of service vulnerability
    An attacker with the ability to send a malicious HTTP request to an affected WLC could cause the device to crash and reload.
    

    Note: The vulnerability can be exploited only via the administrative web-based interface; Web Authentication features are not affected.

    
    This vulnerability is documented in Cisco Bug ID CSCsy27708 ( registered customers only) and has been assigned CVE ID CVE-2009-1166.
    
  • Crafted HTTP or HTTPS request unauthorized configuration modification vulnerability
    An unauthorized configuration modification vulnerability exists in all software versions prior to the first fixed release. A remote, unauthenticated attacker who can submit HTTP or HTTPS requests to the WLC directly could gain full control of the affected device.
    

    Note: The vulnerability can be exploited only by submitting such a request to an IP address that is bound to an administrative interface or VLAN.

    
    The vulnerability is documented by Cisco Bug ID CSCsy44672 ( registered customers only) and has been assigned CVE ID CVE-2009-1167.
    

Workarounds

• The SSH connections denial of service vulnerability identified by Cisco Bug ID CSCsw40789 may be remediated by disabling SSH on the affected device. This workaround requires subsequent management of the device to be performed using the HTTP/HTTPS web management interface or the serial console of the device.

  Additional mitigations that can be deployed on Cisco devices in the network are available in the Cisco Applied Mitigation Bulletin companion document for this advisory, which is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20090727-wlc

Fixed Software

• When considering software upgrades, also consult http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution.

  In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance.

  Vulnerability/Bug ID	Affected Release	First Fixed Version	Recommended Release
  Malformed HTTP or HTTPS authentication response denial of service vulnerability (CSCsx03715)	3.2	3.2.215.0	3.2.215.0
  	4.1	Not Vulnerable	Not Vulnerable
  	4.1M	Not Vulnerable	Not Vulnerable
  	4.2	4.2.205.0	4.2.207.0
  	4.2M	Not Vulnerable	Not Vulnerable
  	5.0	Migrate to 5.2 or 6.0	5.2.193.0 or 6.0.182.0
  	5.1	Migrate to 5.2 or 6.0	5.2.193.0 or 6.0.182.0
  	5.2	5.2.178.0	5.2.193.0 or 6.0.182.0
  	6.0	Not Vulnerable	Not Vulnerable
  SSH connections denial of service vulnerability (CSCsw40789)	3.2	3.2.215.0	3.2.215.0
  	4.1	Migrate to 4.2	4.2.205.0
  	4.1M	Migrate to 5.2, 6.0, or 4.2M	5.2.193.0, 6.0.182.0 or 4.2.176.51 Mesh
  	4.2	4.2.205.0	4.2.207.0
  	4.2M	Not Vulnerable	Not Vulnerable
  	5.0	Migrate to 5.2 or 6.0	5.2.193.0 or 6.0.182.0
  	5.1	5.1.163.0	5.2.193.0 or 6.0.182.0
  	5.2	5.2.178.0	5.2.193.0 or 6.0.182.0
  	6.0	Not Vulnerable	Not Vulnerable
  Crafted HTTP request may cause the WLC to crash (CSCsy27708)	3.2	Not Vulnerable	Not Vulnerable
  	4.1	Migrate to 4.2	4.2.205.0
  	4.1 M	Migrate to 5.2, 6.0, or 4.2M	5.2.193.0, 6.0.182.0 or 4.2.176.51 Mesh
  	4.2	4.2.205.0	4.2.207.0
  	4.2M	Not Vulnerable	Not Vulnerable
  	5.0	Migrate to 5.2 or 6.0	5.2.193.0 or 6.0.182.0
  	5.1	Migrate to 5.2 or 6.0	5.2.193.0 or 6.0.182.0
  	5.2	5.2.191.0	5.2.193.0 or 6.0.182.0
  	6.0	Not Vulnerable	Not Vulnerable
  Crafted HTTP or HTTPS request unauthorized configuration modification vulnerability (CSCsy44672)	3.2	3.2.215.0	3.2.215.0
  	4.1	Migrate to 4.2	4.2.205.0
  	4.1M	Migrate to 5.2, 6.0, or 4.2M	5.2.193.0, 6.0.182.0 or 4.2.176.51 Mesh
  	4.2	4.2.205.0	4.2.207.0
  	4.2M	Not Vulnerable	Not Vulnerable
  	5.0	Migrate to 5.2 or 6.0	5.2.193.0, 6.0.182.0
  	5.1	Migrate to 5.2 or 6.0	5.2.193.0 or 6.0.182.0
  	5.2	5.2.191.0	5.2.193.0 or 6.0.182.0
  	6.0	Not Vulnerable	Not Vulnerable

Exploitation and Public Announcements

• The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities described in this advisory at the time of release.

  The DoS vulnerability documented by CSCsw40789 was discovered during the resolution of customer support cases.

  The unauthorized configuration modification vulnerability documented by CSCsy44672 was found during internal testing.

  The DoS vulnerability documented by CSCsx03715 was discovered by Christoph Bott of SySS GmbH.

  The DoS vulnerability documented by CSCsy27708 was discovered by IBM Research.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20090727-wlc

Revision History

• Revision 1.1	2009-October-15	Added information about WLC Release 3.2 in the Vulnerable Products section and Software Versions and Fixes table
  Revision 1.0	2009-July-27	Initial public release

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