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

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 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.
  
  
  

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
  

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-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
  
  

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.

URL

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

Revision History

• Revision 1.0

  2012-September-12

  Initial public release

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