Summary

• Cisco Nexus, Cisco Unified Computing System (UCS), Cisco MDS 9000 Series Multilayer Switches, and Cisco 1000 Series Connected Grid Routers (CGR) are all based on the Cisco NX-OS operating system.  These products are affected by one or more of the following vulnerabilities:

  • Multiple Cisco Discovery Protocol Vulnerabilities in Cisco NX-OS-Based Products
  • Cisco NX-OS Software SNMP and License Manager Buffer Overflow Vulnerability
  • Cisco NX-OS Software SNMP Buffer Overflow Vulnerability
  • Cisco NX-OS Software Jumbo Packet Denial of Service Vulnerability

  
  Cisco has released software updates that address these vulnerabilities.
  
  This advisory is available at the following link:
  http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130424-nxosmulti

Affected Products

• Cisco products running or based on the Cisco NX-OS Software high-speed routing and switching platform are affected by one or more of the vulnerabilities detailed in this advisory.

  Vulnerable Products

  The following products are vulnerable:
  
  Cisco UCS 6100 = Cisco Unified Computing Server Fabric Interconnect 6100 Series devices
  Cisco UCS 6200 = Cisco Unified Computing Server Fabric Interconnect 6200 Series devices
  Cisco Nexus 7000 = Cisco Nexus 7000 Series devices
  Cisco Nexus 5000 = Cisco Nexus 5010 and Cisco Nexus 5020 devices
  Cisco Nexus 5500 = Cisco Nexus 5500 Series devices
  Cisco Nexus 4000 = Cisco Nexus 4000 Series blade devices
  Cisco Nexus 3000 = Cisco Nexus 3000 Series devices
  Cisco Nexus 1000v = Cisco Nexus 1000v virtual switches and 1010 Virtual Service Appliances
  Cisco MDS 9000 = Cisco MDS 9000 Multilayer Switch/Director Family devices
  Cisco CGR 1000 = Cisco Connected Grid Router 1000 Series devices
  
  The following table details which products are affected by each vulnerability:
  

  	Cisco Nexus 7000	Cisco Nexus 5000	Cisco Nexus 5500	Cisco Nexus 4000	Cisco Nexus 3000	Cisco Nexus 1000V	Cisco MDS 9000	Cisco UCS 6100	Cisco UCS 6200	Cisco CGR 1000
  Multiple CDP Buffer Overflow CVE-2013-1178	X	X	X	X	X	X	X	X	X	X
  SNMP & License Manager Buffer Overflow CVE-2013-1179	X						X
  SNMP Buffer Overflow CVE-2013-1180	X						X
  Jumbo Frame Denial of Service CVE-2013-1181			X		X				X
  Recommended Software	5.2(9)/6.1(1)	5.2(1)N1(4)	5.2(1)N1(4)	4.1(2)E1(1j)	5.0(3)U5(1e)	4.2(1)SV2(1.1)	5.2(8)	2.1.1e	2.1.1e	CG4(1)

  
  Note: The recommended software releases above resolve all issues impacting each platform in the preceding table.

  Products Confirmed Not Vulnerable

  The Cisco Nexus 3548 Switch is not affected by the vulnerabilities described in this document.
  
  The Cisco Nexus 6000 Series of devices is not affected by the vulnerabilities described in this document.
  
  No other Cisco products are currently known to be affected by these vulnerabilities.

Details

• Multiple Cisco Discovery Protocol Vulnerabilities in Cisco NX-OS-Based Products
  
  Cisco NX-OS based devices contain multiple buffer overflow vulnerabilities in Cisco Discovery Protocol (CDP) subsystem. These vulnerabilities could allow an unauthenticated, adjacent attacker to execute arbitrary code with elevated privileges. The vulnerabilities are due to a failure to properly handle malformed Cisco Discovery Protocol packets. An attacker could exploit these vulnerabilities by passing malformed Cisco Discovery Protocol packets to an affected device. Successful exploitation of these vulnerabilities could allow the attacker to execute arbitrary code with elevated privileges.
  
  Because Cisco Discovery Protocol works at the data link layer (Layer 2), an attacker must be able to submit an Ethernet frame directly to an affected device to exploit this vulnerability. This action may be possible in situations where the affected system is part of a bridged network or connected to an unpartitioned device, such as a network hub.
  
  This vulnerability is documented in the following Cisco bug IDs, and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2013-1178.
  
  Cisco Bug IDs:
  

  • UCS 6100/UCS 6200 - CSCtu10630 (registered customers only)
  • Nexus 7000/MDS 9000 - CSCtu10551 (registered customers only)
  • Nexus 5000/Nexus 5500 - CSCtu10550 (registered customers only)
  • Nexus 4000 - CSCtw56581 (registered customers only)
  • Nexus 3000 - CSCtu10548 (registered customers only)
  • Nexus 1000v - CSCtu10544 (registered customers only)
  • CGR 1000 - CSCuf61275 (registered customers only)

  
  Cisco NX-OS Software SNMP and License Manager Buffer Overflow Vulnerability
  
  Cisco NX-OS Software-based devices contain a buffer overflow vulnerability in the SNMP subsystem. An authenticated, remote attacker can exploit the vulnerability by submitting a malicious SNMP query via UDP port 161 to trigger a buffer overflow condition in the SNMP and License Manager components of the device. Successful exploitation could allow the attacker to execute arbitrary code with elevated privileges.
  
  SNMP is disabled by default and must be explicitly configured by an administrator. Because SNMP is primarily a UDP-based protocol, no TCP three-way handshake is required to exploit this vulnerability, and the malicious request could contain a spoofed origin. The attacker must know the configured community strings for SNMP version 1 and version 2. Exploitation also requires a valid username and password when a device is configured for SNMP version 3.
  
  This vulnerability can be triggered via SNMP over IPv4 and SNMP over IPv6.
  
  This vulnerability is documented by Cisco bug ID CSCtx54830 (registered customers only) and has been assigned CVE ID CVE-2013-1179.
  
  Cisco NX-OS Software SNMP Buffer Overflow Vulnerability
  
  Cisco NX-OS based devices contain a buffer overflow vulnerability in the SNMP subsystem.  An authenticated, remote attacker who can submit a malicious SNMP query via UDP port 161 could exploit the vulnerability to trigger a buffer overflow condition in the SNMP component of the device.  Successful exploitation could allow the attacker to execute arbitrary code with elevated privileges. 
  
  SNMP is disabled by default, and must be explicitly configured by an administrator.  Because SNMP is primarily a UDP based protocol, no TCP three-way handshake is required to exploit this vulnerability, and the malicious request could contain a spoofed origin.  The attacker must know the configured community strings for SNMP version 1 and version 2.  Exploitation also requires a valid username and password when a device is configured for SNMP version 3.
  
  This vulnerability can be triggered via SNMP over IPv4 and SNMP over IPv6.
  
  This vulnerability is documented by Cisco bug ID CSCtx54822 (registered customers only) and has been assigned CVE ID CVE-2013-1180.
  
  Cisco NX-OS Software Jumbo Packet Denial of Service Vulnerability
  
  Cisco NX-OS based devices contain a denial of service (DoS) vulnerability.  An unauthenticated, remote attacker who can send a jumbo frame packet to the management interface of an affected device could cause the device to crash and reload.
  
  The vulnerability is due to improper input validation of jumbo packets.  Large packets that are sent through the switching fabric of the device will not trigger the vulnerability.
  
  
  This vulnerability is documented in the following Cisco bug IDs, and has been assigned Common Vulnerabilities and Exposures (CVE) ID CVE-2013-1181.
  
  Cisco Bug IDs:
  

  • UCS  6200- CSCtx17544 (registered customers only)
  • Nexus 5500 - CSCts10593 (registered customers only)
  • Nexus 3000 - CSCtx95389 (registered customers only)

Workarounds

• No on-device workarounds exist for any of the vulnerabilities detailed in this advisory.
  
  Cisco has released an Applied Mitigation Bulletin (AMB) that explains how to detect and mitigate potential exploitation of these vulnerabilities. The AMB Identifying and Mitigating Exploitation of Multiple Vulnerabilities in Cisco NX-OS-Based Products is available at:
  http://tools.cisco.com/security/center/viewAMBAlert.x?alertId=28737

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.
  
  
  Nexus 7000

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	4.1(x) 4.2(x) 5.0(x) 5.1(x) 5.2(3a) and Prior 6.0(x)	5.2(4) 6.1(1)	5.2(9) 6.1(1)
  SNMP & License Manager CVE-2013-1179	4.1(x) 4.2(x) 5.0(x) 5.1(x) 5.2(4) and Prior 6.0(x)	5.2(5) 6.1(1)	5.2(9) 6.1(1)
  SNMP CVE-2013-1180	4.1(x) 4.2(x) 5.0(x) 5.1(x) 5.2(4) and Prior 6.0(x)	5.2(5) 6.1(1)	5.2(9) 6.1(1)

  
  Nexus 5000/Nexus 5500

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	4.0(x) 4.1(x) 4.2(x) 5.0(x)	5.1(3)N1(1)	5.2(1)N1(4)
  Jumbo Frame - Nexus 5500 CVE-2013-1181	4.0(x) 4.1(x) 4.2(x) 5.0(3)N2(1) and Prior	5.0(3)N2(2)	5.2(1)N1(4)

  
  Nexus 4000

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	4.1(2)E1(1g) and Prior	4.1(2)E1(1h)	4.1(2)E1(1j)

  
  Nexus 3000

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	5.0(3)U1(1x) 5.0(3)U1(2x) 5.0(3)U2(1) 5.0(3)U2(2x)	5.0(3)U3(1)	5.0(3)U5(1e)
  Jumbo Frame CVE-2013-1181	5.0(3)U1(1x) 5.0(3)U1(2x) 5.0(3)U2(1) 5.0(3)U2(2x) 5.0(3)U3(1)	5.0(3)U3(2)	5.0(3)U5(1e)

  
  Nexus 1000V

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	4.0(x) 4.2(1)SV1(4b) and Prior	4.2(1)SV1(5.1)	4.2(1)SV2(1.1)

  
  MDS 9000

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	4.1(x) 4.2(x) 5.0(x) 5.2(3) and Prior	5.2(4)	5.2(8)
  SNMP & License Manager CVE-2013-1179	4.1(x) 4.2(x) 5.0(x) 5.2(4) and Prior	5.2(5)	5.2(8)
  SNMP CVE-2013-1180	4.1(x) 4.2(x) 5.0(x) 5.2(4) and Prior	5.2(5)	5.2(8)

  
  Unified Computing System

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	1.0(x) 1.1(x) 1.2(x) 1.3(x) 1.4(x) 2.0(1x) and Prior	2.0(2m) 2.1(1a)	2.1.1e
  Jumbo Frame - UCS 6200 CVE-2013-1181	1.0(x) 1.1(x) 1.2(x) 1.3(x) 1.4(x) 2.0(1t) and prior	2.0(1w)	2.1.1e

  
  Connected Grid Router 1000 Series

  	Affected	First Fixed	Recommended
  Multiple CDP CVE-2013-1178	CG1(4) CG1(5) CG3(1) CG3(2) CG3(3)	CG4(1)	CG4(1)

Exploitation and Public Announcements

• The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
  
  The following vulnerabilities were discovered during an internal security evaluation of NX-OS based products:

  • Multiple Cisco Discovery Protocol Vulnerabilities in Cisco NX-OS-Based Products
  • Cisco NX-OS Software SNMP and License Manager Buffer Overflow Vulnerability
  • Cisco NX-OS Software SNMP Buffer Overflow Vulnerability

  The Cisco NX-OS Software Jumbo Packet Denial of Service Vulnerability was identified by the Cisco TAC while assisting customers.

URL

• http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20130424-nxosmulti

Revision History

• Revision 1.2	2013-April-26	Updated summary table in Affected Products for clarification. Corrected UCS 6100/6200 information for jumbo frame vulnerability in summary table.
  Revision 1.1	2013-April-24	Clarified affected platforms for certain vulnerabilities.
  Revision 1.0	2013-April-24	Initial public release.

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