Advisory ID: cisco-sa-20130116-asa1000v
For Public Release 2013 January 16 16:00 UTC (GMT)
Vulnerability Scoring Details
Software Versions and Fixes
Obtaining Fixed Software
Exploitation and Public Announcements
Status of This Notice: Final
Cisco Security Procedures
Cisco has released free software updates that address this vulnerability.
This advisory is posted at the following link:
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.
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:
Note: The preceding output identifies a policy map with a class map that has H.323 inspection for H.225 messages applied.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
Alternatively, a device that has H.323 inspection for H.225 messages enabled has a configuration similar to the following:
Note: Global application is shown in the preceding example, but the service policy could also be applied to a specific interfaceclass-map inspection_default match default-inspection-traffic ! policy-map global_policy class inspection_default ... inspect h323 h225 ... ! service-policy global_policy global
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.
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 22.214.171.124 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:
Additional dynamic UDP and TCP ports may be negotiated during the H.323 call signaling setup procedure.
1718—Gatekeeper Discovery UDP port
1719—RAS UDP port
1720—TCP control port
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.
Cisco has scored the vulnerability in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this security advisory is in accordance with CVSS version 2.0.
CVSS is a standards-based scoring method that conveys vulnerability severity and helps organizations determine the urgency and priority of a response.
Cisco has provided a base and temporal score. Customers can also compute environmental scores that help determine the impact of the vulnerability in their own networks.
Cisco has provided additional information regarding CVSS at the following link:
Cisco has also provided a CVSS calculator to compute the environmental impact for individual networks at the following link:
CSCuc42812 and CSCuc88741
Calculate the environmental score of CSCuc42812 and CSCuc88741
CVSS Base Score - 7.8
CVSS Temporal Score - 6.4
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 126.96.36.199 and later.
Cisco ASA Software for the Cisco ASA 1000V Cloud Firewall can be downloaded at the following link:
The following example shows how to disable H.323 inspection from the default policy-map:
If H.323 inspection for H.225 messages is required, there are no workarounds.
ASA1000v(config)# policy-map global_policy ASA1000v(config-pmap)# class inspection_default ASA1000v(config-pmap-c)# no inspect h323 h225
Customers may only install and expect support for feature sets they have purchased. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license at http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html.
The effectiveness of any workaround or fix depends on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Because of the variety of affected products and releases, customers should consult their service providers or support organizations to ensure that any applied workaround or fix is the most appropriate in the intended network before it is deployed.
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 Technical Assistance Center (TAC):
- +1 800 553 2447 (toll free from within North America)
- +1 408 526 7209 (toll call from anywhere in the world)
- e-mail: email@example.com
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. Customers without service contracts should request free upgrades through the TAC.
Refer to Cisco Worldwide Contacts at http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, instructions, and e-mail addresses for support in various languages.
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.
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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.
This advisory is posted on Cisco Security Intelligence Operations at the following link:
Additionally, a text version of this advisory is clear signed with the Cisco PSIRT PGP key and circulated among the following e-mail addresses:
Future updates of this advisory, if any, will reside on Cisco.com but may not be announced on mailing lists. Users can monitor this advisory's URL for any updates.
|Revision 1.0||2013-January-16||Initial public release.|