Summary

• A vulnerability in Cisco Adaptive Security Appliance (ASA) Software for the Cisco ASA 1000V Cloud Firewall may cause the Cisco ASA 1000V to reload after processing a malformed H.323 message. Cisco ASA 1000V Cloud Firewall is affected when H.323 inspection is enabled.
  
  Cisco has released software updates that address this vulnerability.
  
  This advisory is posted at the following link:
  
  http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130116-asa1000v
  
  Note:  Only Cisco ASA Software for the Cisco ASA 1000V Cloud Firewall is affected by the vulnerability described in this advisory. Cisco ASA 5500 Series Adaptive Security Appliances, Cisco Catalyst 6500 Series ASA Services Module or Cisco Catalyst 6500 Series Firewall Services Module (FWSM) are not affected by this vulnerability.

Affected Products

• 
  

  Vulnerable Products

  Versions 8.7.1 and 8.7.1.1 of Cisco ASA Software for the Cisco ASA 1000V Cloud Firewall are affected by this vulnerability if H.323 inspection is enabled. H.323 Inspection for both H.225 and Registration, Admission and Status (RAS) messages is enabled by default.
  
  The vulnerability exists only if H.323 inspection for H.225 messages is enabled. H.323 inspection for RAS messages has no effect on this vulnerability.
  
  To determine whether H.323 H.225 inspection is enabled, issue the show service-policy inspect h323 h225 command and verify that a class map is configured with the H.225 inspection engine. If H.323 inspection for H.225 messages is configured, the relevant H.323 output will appear under the referenced class map.
  
  Example output follows:

  ASA1000v# show service-policy inspect h323 h225 
  Global policy: 
    Service-policy: global_policy
      Class-map: inspection_default
        Inspect: h323 h225 _default_h323_map, packet 0, lock fail 0, drop 0, reset-drop 0
                 tcp-proxy: bytes in buffer 0, bytes dropped 0
          h245-tunnel-block drops 0 connection

  
  

  Note: The preceding output identifies a policy map with a class map that has H.323 inspection for H.225 messages applied.
  
  Alternatively, a device that has H.323 inspection for H.225 messages enabled has a configuration similar to the following:
  
  

  class-map inspection_default 
   match default-inspection-traffic
  !
  policy-map global_policy
   class inspection_default
    ...
    inspect h323 h225
    ...
  !
  service-policy global_policy global

  
  

  Note: Global application is shown in the preceding example, but the service policy could also be applied to a specific interface
  
  Customers who use Cisco Adaptive Security Device Manager (ASDM) to manage devices can check the Service Policy section under the global or interface specific policies to determine whether the inspection is enabled.
  
  Customers who use Cisco Virtual Network Management Center (VNMC) to manage multiple devices can locate the Packet Inspection section under Policy Management > Security Policies > Root > Tenant > Data Center > Policies to determine whether the inspection is enabled.

  
  To determine the version of Cisco ASA Software for the Cisco ASA 1000V Cloud Firewall that is running, issue the show version command from the Cisco ASA 1000V command line.
  

  
  

  The following example shows a system that is running an affected software version (8.7.1):

  
  

  ASA1000v(config)# show version
  Cisco Adaptive Security Appliance Software Version 8.7(1)
  Device Manager Version 6.3(5)

  
  Customers who use the Cisco Adaptive Security Device Manager (ASDM) to manage their devices can find the version of the software displayed in the table in the login window or in the upper left corner of the ASDM window. 
  

  
  

  Alternatively, version information can be obtained from the Summary tab of the Cisco ASA 1000V Cloud Firewall resource in the VMware vCenter Server.

  Products Confirmed Not Vulnerable

  With the exception of Cisco ASA 1000V Cloud Firewall, no other Cisco products are currently known to be affected by this vulnerability.
  

Details

• The Cisco ASA 1000V Cloud Firewall is a virtual security appliance that secures the tenant edge in multitenant private and public cloud deployments. It runs on VMware vSphere Hypervisor software and the Cisco Nexus 1000V Series Switch exclusively.
  
  The Cisco ASA 1000V Cloud Firewall allows virtual machines (VMs) in a virtual data center to access the Internet securely, functions as the default gateway for the VMs, and protects against network-based attacks.
  
  Cisco ASA Software for the 1000V Cloud Firewall versions 8.7.1 and 8.7.1.1 contain a vulnerability that could allow an unauthenticated, remote attacker to cause a reload of the Cisco 1000V Cloud Firewall.
  
  The vulnerability is due to incorrect handling of malformed H.323 packets. An attacker could exploit this vulnerability by sending a crafted H.323 packet through the affected device. An exploit could allow the attacker to reload the Cisco ASA 1000V Cloud Firewall, resulting in denial of service (DoS) condition.
  
  A Cisco ASA 1000V device that is configured to inspect H.323 through-the-box traffic may reload when a malformed H.323 IPv4 packet is received. 
  
  The H.323 control channel handles H.225, H.245 and H.323 RAS messages. H.323 inspection uses the following well-known ports:
  

  1718—Gatekeeper Discovery UDP port
  1719—RAS UDP port
  1720—TCP control port

  Additional dynamic UDP and TCP ports may be negotiated during the H.323 call signaling setup procedure.
  
  A malformed packet sent to any of the well-known ports used by H.323 inspection, or to ports dynamically negotiated by H.323 call signaling setup, may trigger this vulnerability.
  
  Only through-the-box traffic may trigger this vulnerability. Cisco ASA 1000V Cloud Firewall is affected only if H.323 inspection for H.225 messages is enabled.
  
  Cisco ASA 1000V Cloud Firewall does not support H.323 inspection over IPv6 transport.
  
  This vulnerability is documented in Cisco Bug ID CSCuc42812 (registered customers only) and CSCuc88741 (registered customers only) and has been assigned CVE-2012-5419.
  

Workarounds

• If H.323 inspection is not required, it can be disabled so the device is no longer affected by the vulnerability. Administrators can disable H.323 inspection for H.225 messages by issuing the no inspect h323 h225 command in class configuration submode in the policy map configuration. H.323 inspection for H.225 messages should be disabled for the workaround to be effective.
  
  The following example shows how to disable H.323 inspection from the default policy-map:
  

  ASA1000v(config)# policy-map global_policy
  ASA1000v(config-pmap)# class inspection_default
  ASA1000v(config-pmap-c)# no inspect h323 h225

  If H.323 inspection for H.225 messages is required, there are no workarounds.

Fixed Software

• When considering software upgrades, customers are advised to consult the Cisco Security Advisories and Responses archive at http://www.cisco.com/go/psirt and review subsequent advisories 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. 
  
  This vulnerability has been fixed in Cisco ASA Software for the Cisco ASA 1000V Cloud Firewall version 8.7.1.3 and later.
  
  Cisco ASA Software for the Cisco ASA 1000V Cloud Firewall can be downloaded at the following link:
  

  
  http://software.cisco.com/download/type.html?mdfid=284145419&catid=null
  

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.

  This vulnerability was found during internal testing.

URL

• http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130116-asa1000v

Revision History

• Revision 1.0

  2013-January-16

  Initial public release.

  Show Less