Cisco Security Advisory

Cisco ASA-CX and Cisco PRSM Log Retention Denial of Service Vulnerability

Advisory ID: cisco-sa-20120912-asacx

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120912-asacx

Revision 1.0

For Public Release 2012 September 12 16:00  UTC (GMT)


Summary

Cisco ASA-CX Context-Aware Security appliance and Cisco Prime Security Manager (PRSM) contain a denial of service (DoS) vulnerability in versions prior to 9.0.2-103.

Successful exploitation of this vulnerability on the Cisco ASA-CX could cause the device to stop processing user traffic and prevent management access to the Cisco ASA-CX.
Successful exploitation of this vulnerability on the Cisco PRSM could cause the software to become unresponsive and unavailable.

There are no workarounds for this vulnerability, but some mitigations are available.

Cisco has released free software updates that address this vulnerability. This advisory is available at the following link:
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120912-asacx

Affected Products


Vulnerable Products


All versions of Cisco ASA-CX Content-Aware Security and Cisco PRSM software prior to 9.0.2-103 are affected by the vulnerability in this advisory.


Determining Cisco ASA-CX Context-Aware Security and Cisco Prime Security Manager Software Versions

To determine the running version of Cisco ASA-CX software, issue the show version command from the Cisco ASA-CX command line interface, to which an administrator can get access via serial console, SSH session to the ASA-CX management interface, or a session opened from the parent ASA using the session command.

The following example shows Cisco ASA-CX software Version 9.0.1(40) and Cisco PRSM Version 9.0.1(40):

	asacx> show version
	Cisco ASA CX Platform  9.0.1 (40)
	Cisco Prime Security Manager 9.0.1 (40)

Customers using Cisco PRSM to manage Cisco ASA-CX devices can locate the software version of Cisco ASA-CX in the Device > Devices part of the Cisco Prime Security Manager window.


To determine the running version of Cisco PRSM software, issue the show version command from the Cisco PRSM command line interface, to which an administrator can get access to via PRSM VMware console, or SSH session to the Cisco PRSM management interface.

The following example shows Cisco PRSM software Version 9.0.1(40):

	prsm> show version
	Cisco Prime Security Manager 9.0.1 (40) Multi Device prsm-vm



Customers using HTTPS to access Cisco PRSM can locate the software version of Cisco PRSM in the Administration > About PRSM part of the Cisco Prime Security Manager window.


Products Confirmed Not Vulnerable

Cisco ASA 5500 Series Adaptive Security Appliances, Cisco ASA Services Module (ASA-SM) and Cisco Catalyst 6500 Series Firewall Services Module (FWSM) are not affected by this vulnerability.

No other Cisco products are currently known to be affected by this vulnerability. 

Details

The Cisco ASA CX Context-Aware Security is an add-on services module that extends the ASA platform with context-aware capabilities for additional visibility and control.
The Cisco Prime Security Manager (PRSM) is the multi-device management platform for Cisco ASA-CX.

The Cisco ASA-CX and Cisco PRSM contain a vulnerability that could allow an unauthenticated remote attacker to cause a DoS condition.

An attacker could exploit this vulnerability by sending certain types of IPv4 packets to the management interface of the Cisco ASA-CX or Cisco PRSM. As a result, the log files grow and consume the /var/log partition. Once the /var/log partition is full, the Cisco ASA-CX module or Cisco PRSM will become unresponsive.

Successful exploitation on a Cisco ASA-CX device could cause the Cisco ASA-CX to become unresponsive and stop processing user traffic.
Successful exploitation on a Cisco PRSM software could cause the Cisco PRSM to become unresponsive.

Only user traffic specifically directed towards the Cisco ASA-CX by the Modular Policy Framework (MPF) configuration on the parent Cisco ASA is affected by the vulnerability in this advisory.
Management traffic from Cisco PRSM to Cisco ASA-CX is also affected by this vulnerability.


How to determine if the vulnerability has been exploited

To determine if the vulnerability has been exploited on the affected device, issue the show diskusage command from the command line interface.

The following example shows the output of an affected Cisco ASA-CX or Cisco PRSM where /var/log utilization has reached 100% of use:

	asacx>show diskusage

FILESYSTEM                          SIZE      AVAILABLE           USE%
/                                   3.0G           2.0G            28%
/boot                             407.2M         307.2M            20%
/var                                9.8G           9.2G             2%
/var/data                         498.1G         466.6G             1%
/var/packages                       9.8G           8.7G             7%
/var/config                         1.1G        1004.5M             3%
/var/db                             3.9G           3.6G             4%
/var/log                            3.9G              0           100%
/var/local                          3.9G           3.6G             4%
/var/data/diagnostics              15.7G          14.8G             1%
/var/data/cores                    15.7G          14.8G             1%

This vulnerability is documented in Cisco bug ID CSCub70603 (registered customers only) for Cisco ASA-CX Context-Aware Security and Cisco Prime Security Manager and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2012-4629. 


Vulnerability Scoring Details

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:

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

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

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



CSCub70603

Calculate the environmental score of CSCub70603

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


Impact

Successful exploitation of the vulnerability on the Cisco ASA-CX Context-Aware Security appliance may cause the device to become unresponsive and stop processing user traffic.

Successful exploitation of this vulnerability could cause the Cisco PRSM to become unresponsive and unavailable for managing Cisco ASA-CX software.

Software Versions and Fixes

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-CX Context-Aware Security and Cisco Prime Security Manager Software versions 9.0.2-103 and later.


Cisco ASA-CX Context-Aware Security Software can be downloaded at the following link:

http://www.cisco.com/cisco/pub/software/portal/select.html?&mdfid=284325223&softwareid=284399944 


Cisco Prime Security Manager Software can be downloaded at the following link:


http://www.cisco.com/cisco/pub/software/portal/select.html?&mdfid=284397197&flowid=33362&softwareid=284399945


Workarounds

There are no workarounds for this vulnerability.

If the vulnerability has been exploited on the Cisco ASA-CX and the traffic is interrupted, as a mitigation, Modular Policy Framework (MPF) configuration on the Cisco ASA that is used to direct the user traffic towards the Cisco ASA-CX can be removed. This will cause all user traffic to bypass Cisco ASA-CX module inspection and allow it to pass through the Cisco ASA.

The following example shows how to disable the redirecting of web traffic to the Cisco ASA-CX from the Cisco ASA firewall:

hostname(config)# class-map http_traffic
hostname(config-cmap)# match port tcp eq 80
hostname(config)# policy-map http_traffic_policy
hostname(config-pmap)# class http_traffic
hostname(config-pmap-c)# no cxsc
There are no similar mitigations available for Cisco Prime Security Manager.

Additional mitigations that can be deployed on Cisco devices within the network are available in the companion document for this Advisory: http://tools.cisco.com/security/center/viewAMBAlert.x?alertId=26840

Obtaining Fixed Software

Cisco has released free software updates that address the vulnerability described in this advisory. Prior to deploying software, customers are advised to consult their maintenance providers or check the software for feature set compatibility and known issues that are specific to their environments.

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.

Customers with Service Contracts

Customers with contracts should obtain upgraded software through their regular update channels. For most customers, upgrades should be obtained through the Software Navigator on Cisco.com at http://www.cisco.com/cisco/software/navigator.html.

Customers Using Third-Party Support Organizations

Customers with Cisco products that 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 organization for assistance with the appropriate course of action.

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 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 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: tac@cisco.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.

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.

The vulnerability described in this security advisory was found during the resolution of a customer service request.

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 Security Intelligence Operations at the following link:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120912-asacx

Additionally, a text version of this advisory is clear signed with the Cisco PSIRT PGP key and circulated among the following e-mail addresses:

  • 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

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 History

Revision 1.0 2012-September-12 Initial public release

Cisco Security Procedures

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


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