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Cisco Security Advisory

Multiple Vulnerabilities in Cisco Wireless LAN Controllers

Advisory ID: cisco-sa-20100908-wlc

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100908-wlc

Revision 1.1

For Public Release 2010 September 8 16:00  UTC (GMT)


Summary

The Cisco Wireless LAN Controller (WLC) product family is affected by these vulnerabilities:

  • Two denial of service (DoS) vulnerabilities
  • Three privilege escalation vulnerabilities
  • Two access control list (ACL) bypass vulnerabilities

Note: These vulnerabilities are independent of one another. A device may be affected by one vulnerability and not affected by another.

Cisco has released free software updates that address these vulnerabilities.

There are no workarounds to mitigate these vulnerabilities.

This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100908-wlc.

Affected Products

Vulnerable Products

These products are each affected by at least one vulnerability covered in this Security Advisory:

  • Cisco 2000 Series WLCs

  • Cisco 2100 Series WLCs

  • Cisco 4100 Series WLCs

  • Cisco 4400 Series WLCs

  • Cisco 5500 Series WLCs

  • Cisco Wireless Services Modules (WiSMs)

  • Cisco WLC Modules for Integrated Services Routers (ISRs)

  • Cisco Catalyst 3750G Integrated WLCs

DoS Vulnerabilities

The Cisco WLC product family is affected by two DoS vulnerabilities:

  • Internet Key Exchange (IKE) DoS Vulnerability
  • HTTP DoS Vulnerability

The IKE DoS vulnerability affects Cisco WLC software versions 3.2 and later. The HTTP DoS vulnerability affects Cisco WLC software versions 4.2 and later.

Privilege Escalation Vulnerabilities

The privilege escalation vulnerabilities affect Cisco WLC software versions 4.2 and later.

CPU ACL Bypass Vulnerabilities

One of the two ACL bypass vulnerabilities affects Cisco WLC software versions 4.1 and later. The second ACL bypass vulnerability affects Cisco WLC software versions 6.0.x.

Determination of Software Versions

Administrators can use these instructions to determine the software version that is running on the Cisco WLCs (using the web or command-line interface) or on the Cisco WiSM (using commands on the Cisco Catalyst 6500 Series Switch and Cisco 7600 Series Router).

Cisco Wireless Controllers

To determine the WLC version that is running in a given environment, use one of these 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 Cisco WLC Module in an ISR will need to issue the service-module wlan-controller <slot/port> 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 <Stack-Member-Number> 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 this 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
    <output suppressed>

Cisco WiSMs

Use the show wism module <module number> controller 1 status command on a Cisco Catalyst 6500 Series Switch and Cisco 7600 Series Router if they are using a WiSM. Note the software version as demonstrated in this 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

No other Cisco products are currently known to be affected by these vulnerabilities.

Details

Cisco WLCs and Cisco WiSMs 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) and the Control and Provisioning of Wireless Access Points (CAPWAP) protocol.

The Cisco WLC family of devices is affected by 2 denial of service vulnerabilities, 3 privilege escalation vulnerabilities, and 2 access control list bypass vulnerabilities. The following are the details about these vulnerabilities.

IKE Denial of Service Vulnerability

An attacker with the ability to send a malicious IKE packet to an affected Cisco WLC could cause the device to crash and reload. This vulnerability can be exploited from both wired and wireless segments.

Note: IKE is enabled by default in the WLC and cannot be disabled. Only traffic destined to the Cisco WLC could trigger this vulnerability. Transient traffic will not trigger this vulnerability.

This vulnerability is documented in Cisco Bug ID CSCta56653 ( registered customers only) and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2010-0574.

HTTP Denial of Service Vulnerability

An authenticated attacker with the ability to send a series of malicious HTTP packets to an affected Cisco WLC could cause the device to reload. This vulnerability can be exploited from both wired and wireless segments. A TCP three-way handshake is needed in order to exploit this vulnerability.

Note: Only traffic destined to the Cisco WLC could trigger this vulnerability. Transient traffic will not trigger this vulnerability. WebAuth or guest access is not affected by this vulnerability.

This vulnerability is documented in Cisco Bug ID CSCtd16938 ( registered customers only) and has been assigned CVE ID CVE-2010-2841.

Privilege Escalation Vulnerabilities

Three privilege escalation vulnerabilities exist in the Cisco WLCs that could allow an authenticated attacker with read-only privileges to modify the device configuration.

These vulnerabilities are documented in Cisco Bug IDs CSCtc91431 ( registered customers only) , CSCsz66726 ( registered customers only) , and CSCtc93837 ( registered customers only) ;and have been assigned CVE IDs CVE-2010-2842, CVE-2010-2843, and CVE-2010-3033.

Access Control List Bypass Vulnerabilities

ACLs can be configured in the Cisco WLCs and applied to data traffic to and from wireless clients or to all traffic that is destined for the controller CPU. After ACLs are defined, they can be applied to the management interface, the access point manager (AP-manager) interface, or any of the dynamic interfaces for client data traffic or to the Network Processing Unit (NPU) interface for traffic to the controller CPU. Two vulnerabilities exist in the Cisco WLCs that could allow an unauthenticated attacker to bypass policies that should be enforced by CPU-based ACLs. No other ACL types are affected by these vulnerabilities.

Note: CPU-based ACLs are configured and applied by navigating to Security > Access Control Lists > CPU Access Control Lists in the Cisco WLC web management interface. When CPU-based ACLs are enabled, they are applicable to both wireless and wired traffic.

These vulnerabilities are documented in Cisco Bug IDs CSCta66931 ( registered customers only) and CSCtf36051 ( registered customers only) ; and have been assigned CVE IDs CVE-2010-0575 and CVE-2010-3034.

Vulnerability Scoring Details

Cisco has provided scores for the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this Security Advisory is done in accordance with CVSS version 2.0.

CVSS is a standards-based scoring method that conveys vulnerability severity and helps determine urgency and priority of response.

Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks.

Cisco has provided an FAQ to answer additional questions regarding CVSS at

http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html.

Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at

http://intellishield.cisco.com/security/alertmanager/cvss.

CSCta56653 - WLC may reload when receiving crafted IKE packets

Calculate the environmental score of CSCta56653

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

CSCtd16938 - WLC crash after passing invalid arguments to emweb

Calculate the environmental score of CSCtd16938

CVSS Base Score - 6.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

Single

None

None

Complete

CVSS Temporal Score - 5.6

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

CSCtc91431, CSCsz66726, and CSCtc93837- Privilege Escalation vulnerabilities

Calculate the environmental score of CSCtc91431, CSCsz66726, and CSCtc93837

CVSS Base Score - 9.0

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

Single

Complete

Complete

Complete

CVSS Temporal Score - 7.8

Exploitability

Remediation Level

Report Confidence

High

Official-Fix

Confirmed

CSCta66931and CSCtf36051 - CPU ACL bypass vulnerabilities

Calculate the environmental score of CSCta66931 and CSCtf36051

CVSS Base Score - 5.0

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

Partial

None

None

CVSS Temporal Score - 4.1

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

Impact

Successful exploitation of the DoS vulnerabilities could cause an affected device to reload. Repeated exploitation could result in a sustained DoS condition.

Successful exploitation of the privilege escalation vulnerabilities could allow an authenticated attacker with read-only privileges to modify the device configuration.

Successful exploitation of the ACL bypass vulnerabilities could allow an attacker to bypass policies that should be enforced by CPU-based ACLs.

Software Versions and Fixes

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.

If a given release train is vulnerable, then the earliest possible releases that contain the fix (along with the anticipated date of availability for each, if applicable) are listed in the "First Fixed Release" column of the table. A device running a release in the given train that is earlier than the release in a specific column (less than the First Fixed Release) is known to be vulnerable.

Vulnerability/Bug ID

Affected Release

First Fixed Version

IKE DoS Vulnerability (CSCta56653)

3.2

3.2.215.0

4.0

Vulnerable; Migrate to 4.2

4.1

Vulnerable; Migrate to 4.2

4.1M

Vulnerable; Migrate to 4.2M

4.2

4.2.205.0

4.2M

4.2.207.54M

5.0

Vulnerable; Migrate to 6.0

5.1

Vulnerable; Migrate to 6.0

5.2

5.2.193.11

6.0

6.0.188.0

7.0

Not Vulnerable

HTTP DoS Vulnerability (CSCtd16938)

3.2

Not Vulnerable

4.0

Vulnerable; Migrate to 4.2

4.1

Not Vulnerable

4.1M

Not Vulnerable

4.2

4.2.209.0

4.2M

4.2.207.54M

5.0

Vulnerable; Migrate to 6.0

5.1

Vulnerable; Migrate to 6.0

5.2

5.2.193.11

6.0

6.0.196.0

7.0

Not Vulnerable

Privilege Escalation Vulnerabilities (CSCtc91431, CSCsz66726, and CSCtc93837)

3.2

Not Vulnerable

4.0

Vulnerable; Migrate to 4.2

4.1

Vulnerable; Migrate to 4.2

4.1 M

Vulnerable; Migrate to 4.2M

4.2

4.2.209.0

4.2M

4.2.207.54M

5.0

Vulnerable; Migrate to 6.0

5.1

Vulnerable; Migrate to 6.0

5.2

5.2.193.11

6.0

6.0.188.0

7.0

Not Vulnerable

ACL Bypass Vulnerabilities (CSCta66931 and CSCtf36051)

3.2

Not Vulnerable

4.0

Not Vulnerable

4.1

Not Vulnerable

4.1M

Not Vulnerable

4.2

4.2.207.0

4.2M

4.2.207.54M

5.0

Vulnerable; Migrate to 6.0

5.1

Vulnerable; Migrate to 6.0

5.2

Not Vulnerable

6.0

6.0.199.0

7.0

Not Vulnerable

Recommended Releases

The "Recommended Release" table lists the releases which have fixes for all the published vulnerabilities at the time of this Advisory. Cisco recommends upgrading to a release equal to or later than the release in the "Recommended Releases" table.

Affected Release

Recommended Release

3.2

3.2.215.0

4.0

Vulnerable; Migrate to 4.2

4.1

Vulnerable; Migrate to 4.2

4.1M

Vulnerable; Migrate to 4.2M

4.2

4.2.209.0

4.2M

4.2.207.54M

5.0

Vulnerable; Migrate to 6.0

5.1

Vulnerable; Migrate to 6.0

5.2

Non FIPS Customers migrate to 6.0

6.0

6.0.199.4

7.0

Not Vulnerable

Note: Cisco WLC Software version 5.2.193.11 is a FIPS certified image. Customers not running FIPS images are recommended to migrate to Cisco WLC software 6.0.199.4 or later.

Customers running 4.1M with a mixture of LAP1505/LAP1510 and LAP1522/LAP1524 units will need to refer to the Mesh and Mainstream Releases on the Controller section of the document Cisco Wireless Mesh Access Points, Design and Deployment Guide, Release 7.0.


Workarounds

There are no available workarounds to mitigate any of these vulnerabilities.

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: http://tools.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20100908-wlc.

Obtaining Fixed Software

Cisco has released free software updates that address these vulnerabilities. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment.

Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html , or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml .

Do not contact psirt@cisco.com or security-alert@cisco.com for software upgrades.

Customers with Service Contracts

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, this means that upgrades should be obtained through the Software Center on Cisco's worldwide website at http://www.cisco.com.

Customers Using Third-Party Support Organizations

Customers whose Cisco products are provided or maintained through prior or existing agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers should contact that support organization for guidance and assistance with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix is dependent on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Due to the variety of affected products and releases, customers should consult with their service provider or support organization to ensure any applied workaround or fix is the most appropriate for use in the intended network before it is deployed.

Customers Without Service Contracts

Customers who purchase direct from Cisco but do not hold a Cisco service contract, and customers who purchase through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should acquire upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows.

  • +1 800 553 2447 (toll free from within North America)
  • +1 408 526 7209 (toll call from anywhere in the world)
  • e-mail: tac@cisco.com

Customers should have their product serial number available and be prepared to give the URL of this notice as evidence of entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC.

Refer to http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, and instructions and e-mail addresses for use in various languages.

Exploitation and Public Announcements

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

These vulnerabilities were found during internal testing and during the troubleshooting of customer service requests.

Status of This Notice: Final

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

A stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors.


Distribution

This advisory is posted on Cisco's worldwide website at :

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100908-wlc

In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail and Usenet news recipients.

  • cust-security-announce@cisco.com
  • first-bulletins@lists.first.org
  • bugtraq@securityfocus.com
  • vulnwatch@vulnwatch.org
  • cisco@spot.colorado.edu
  • cisco-nsp@puck.nether.net
  • full-disclosure@lists.grok.org.uk
  • comp.dcom.sys.cisco@newsgate.cisco.com

Future updates of this advisory, if any, will be placed on Cisco's worldwide website, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the above URL for any updates.


Revision History

Revision 1.1

2010-September-09

Added information for Release 4.0.

Revision 1.0

2010-September-08

Initial public release.

Cisco Security Procedures

Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html. This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt.


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