Cisco IOS Software High Priority Queue Denial of Service Vulnerability

Summary

• A vulnerability in the packet driver code of Cisco IOS Software could allow an unauthenticated, remote attacker to cause a reload of the affected device, resulting in a denial of service (DoS) condition.
  
  The vulnerability is due to how the packet driver code handles packets that belong to protocols that engage high priority queues, such as Virtual Switching Systems (VSS) or Bidirectional Forwarding Detection (BFD). An attacker could exploit this vulnerability by sending a number of BFD or VSS packets to be processed by an affected device. An exploit could allow the attacker to cause a reload of the affected device that would lead to a DoS condition.
  
  Cisco has confirmed the vulnerability in a security notice and released software updates.
  
  To exploit this vulnerability, an attacker would need access to the same broadcast or collision domain as the targeted device. This access requirement may reduce the possibility of a successful exploit.

Affected Products

• Customers are advised to consult Cisco bug IDs CSCug41049 and CSCue61890 for a complete list of affected product versions.

  Vulnerable Products

  At the time this alert was first published, Cisco IOS Software Release 15.2(1)E was vulnerable. Later releases of Cisco IOS Software may also be vulnerable.

  Products Confirmed Not Vulnerable

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

Workarounds

• Administrators are advised to apply the appropriate updates.
  
  It is critical to prevent unauthorized direct communication to network devices. Restrict network traffic destined for the network infrastructure to protect against reconnaissance and DoS attacks. For configuration details, see Protecting Your Core: Infrastructure Protection Access Control Lists.
  
  Administrators are advised to monitor network traffic for security-related network activity. Cisco NetFlow can identify such activity. For more information about Cisco NetFlow, see Introduction to Cisco IOS NetFlow - A Technical Overview.
  
  To mitigate denial of service attacks, apply hardware rate limiter features to limit packets that require CPU processing. See vendor documentation for specific configuration instructions. For hardware rate limiting configuration details, see Cisco Catalyst 6500 Denial of Service (DoS) Protection Configuration Guide.
  
  Administrators are advised to monitor affected systems.
  

Fixed Software

• Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at tac@cisco.com for assistance.
  

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.

URL

• http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/Cisco-SA-20140331-CVE-2014-2131

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial Release	NA	Final	2014-Mar-31

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