Summary

• The Secure Shell (SSH) server implementation in Cisco IOS Software and Cisco IOS XE Software contains a denial of service (DoS) vulnerability in the SSH version 2 (SSHv2) feature. An unauthenticated, remote attacker could exploit this vulnerability by attempting a reverse SSH login with a crafted username.  Successful exploitation of this vulnerability could allow an attacker to create a DoS condition by causing the device to reload.  Repeated exploits could create a sustained DoS condition.

  
  

  The SSH server in Cisco IOS Software and Cisco IOS XE Software is an optional service, but its use is highly recommended as a security best practice for the management of Cisco IOS devices.  Devices that are not configured to accept SSHv2 connections are not affected by this vulnerability.

  
  

  Cisco has released software updates that address this vulnerability.  This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120328-ssh
  

  Note: The March 28, 2012, Cisco IOS Software Security Advisory bundled publication includes nine Cisco Security Advisories. Each advisory lists the Cisco IOS Software releases that correct the vulnerability or vulnerabilities detailed in the advisory as well as the Cisco IOS Software releases that correct all vulnerabilities in the March 2012 bundled publication.
  
  Individual publication links are in "Cisco Event Response: Semi-Annual Cisco IOS Software Security Advisory Bundled Publication" at the following link:

  http://www.cisco.com/web/about/security/intelligence/Cisco_ERP_mar12.html

  
  

Affected Products

• 
  

  Vulnerable Products

  Cisco devices that are running affected Cisco IOS Software or Cisco IOS XE Software versions are vulnerable when they have the SSH server enabled and allow SSHv2 logins.  Only SSHv2 is affected.
  
  To determine if SSH is enabled, use the show ip ssh command.  

    Router#show ip ssh 

    SSH Enabled - version 2.0 

    Authentication timeout: 120 secs; Authentication retries: 3

  The previous output shows that SSH is enabled on this device and that the SSH protocol major version that is being supported is 2.0. Possible values for the SSH protocol versions that are reported by Cisco IOS are: 

  • 1.5: only SSH protocol version 1 is enabled 
  • 1.99: SSH protocol version 2 with SSH protocol version 1 compatibility enabled 
  • 2.0: only SSH protocol version 2 is enabled 

  The SSH server is not available in all IOS images. If the show ip ssh command is not available, the device is not vulnerable. Devices that do not support SSHv2 are not vulnerable.
  

  To determine the Cisco IOS Software release that is running on a Cisco product, administrators can log in to the device and issue the show version command to display the system banner. The system banner confirms that the device is running Cisco IOS Software by displaying text similar to "Cisco Internetwork Operating System Software" or "Cisco IOS Software." The image name displays in parentheses, followed by "Version" and the Cisco IOS Software release name. Other Cisco devices do not have the show version command or may provide different output.

  The following example identifies a Cisco product that is running Cisco IOS Software Release 15.0(1)M1 with an installed image name of C3900-UNIVERSALK9-M:

  Router> show version 
  Cisco IOS Software, C3900 Software (C3900-UNIVERSALK9-M), Version 15.0(1)M1, RELEASE SOFTWARE (fc1)
  Technical Support: http://www.cisco.com/techsupport
  Copyright (c) 1986-2009 by Cisco Systems, Inc.
  Compiled Wed 02-Dec-09 17:17 by prod_rel_team

  !--- output truncated 

  Additional information about Cisco IOS Software release naming conventions is available in "White Paper: Cisco IOS and NX-OS Software Reference Guide" at http://www.cisco.com/web/about/security/intelligence/ios-ref.html.

  
  

  Products Confirmed Not Vulnerable

  Cisco IOS-XR is not affected by this vulnerability.

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

Details

• Secure Shell (SSH) is a protocol which provides a secure remote access connection to network devices. 

  The SSH server implementation in Cisco IOS Software and Cisco IOS XE Software contains a DoS vulnerability in the SSH version 2 (SSHv2) feature that could allow an unauthenticated remote attacker to cause a device to reload.  An attacker could exploit this vulnerability by attempting a reverse SSH login with a crafted username.  Successful exploitation of this vulnerability could allow an attacker to create a DoS condition by causing the device to reload.  Repeated exploits could create a sustained DoS condition.

  The SSH server in Cisco IOS Software and Cisco IOS XE Software is an optional service, but its use is highly recommended as a security best practice for management of Cisco IOS devices. SSH can be configured as part of the AutoSecure feature in the initial configuration of IOS devices, AutoSecure run after initial configuration, or manually. SSH is enabled any time RSA keys are generated such as when an http secure-server or trust points for digital certificates are configured.  Devices that are not configured to accept SSHv2 connections are not affected by this vulnerability.

  A complete TCP three-way handshake is required to exploit this vulnerability.  Reverse SSH traffic uses TCP port 22 by default.

  
  

  This vulnerability has been documented in Cisco Bug ID CSCtr49064 and has been assigned the Common Vulnerabilities and Exposures (CVE) ID CVE-2012-0386.

Workarounds

• If disabling the IOS SSH Server is not feasible, the following workarounds may be useful to some customers in their environments.

  SSH version 1

  This vulnerability only affects SSHv2, so it can be temporarily mitigated by applying the ip ssh version 1 global configuration command until a software update can be completed.  Customers should be aware of the limitations and vulnerabilities of SSH version 1 protocol before applying this workaround.

  vty Access Class

  It is possible to limit the exposure of the Cisco device by applying a vty access class to allow only known, trusted hosts to connect to the device via SSH.

  For more information on restricting traffic to a vty, please consult: http://www.cisco.com/en/US/docs/ios/12_2/ipaddr/command/reference/1rfip1.html#wp1017389.

  The following example permits access to the vty lines from the 192.168.1.0/24 netblock and the single IP address 172.16.1.2 while denying access from anywhere else:

  Router(config)# access-list 1 permit 192.168.1.0 0.0.0.255
  Router(config)# access-list 1 permit host 172.16.1.2
  Router(config)# line vty 0 4
  Router(config-line)# access-class 1 in

  Different Cisco platforms support a different amount of terminal lines. Check your device's configuration to determine the correct number of terminal lines for your platform.

  Infrastructure Access Control Lists

  Although it is often difficult to block traffic transiting your network, it is possible to identify traffic that should never be allowed to target your infrastructure devices and block that traffic at the border of your network. Infrastructure access control lists (iACLs) are considered a network security best practice and should be considered as a long-term addition to good network security as well as a workaround for this specific vulnerability. The ACL example shown below should be included as part of the deployed infrastructure access-list, which will protect all devices with IP addresses in the infrastructure IP address range.

  A sample access list for devices running Cisco IOS is below:

  !--- Permit SSH services from trusted hosts destined 

  !--- to infrastructure addresses.

  access-list 150 permit tcp TRUSTED_HOSTS MASK INFRASTRUCTURE_ADDRESSES MASK eq 22

  !--- Deny SSH packets from all other sources destined to infrastructure addresses.

  access-list 150 deny   tcp any INFRASTRUCTURE_ADDRESSES MASK eq 22

  !--- Permit all other traffic to transit the device.

  access-list 150 permit IP any any

  interface serial 2/0

    ip access-group 150 in

  The white paper titled "Protecting Your Core: Infrastructure Protection Access Control Lists" presents guidelines and recommended deployment techniques for infrastructure protection access lists. This white paper is located at http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801a1a55.shtml.

  Control Plane Policing

  The Control Plane Policing (CoPP) feature may be used to mitigate these vulnerabilities. In the following example, only SSH traffic from trusted hosts with receive destination IP addresses is permitted to reach the route processor (RP).

  Note: Dropping traffic from unknown or untrusted IP addresses may affect hosts with dynamically assigned IP addresses from connecting to the Cisco IOS device.

      access-list 152 deny   tcp TRUSTED_ADDRESSES MASK any eq 22

      access-list 152 permit tcp any any eq 22

      !

      class-map match-all COPP-KNOWN-UNDESIRABLE

       match access-group 152

      !

      !

      policy-map COPP-INPUT-POLICY

       class COPP-KNOWN-UNDESIRABLE

        drop

      !

      control-plane

       service-policy input COPP-INPUT-POLICY

  In the above CoPP example, the ACL entries that match the exploit packets with the permit action result in these packets being discarded by the policy-map drop function, while packets that match the deny action are not affected by the policy-map drop function.

  Additional information on the configuration and use of the CoPP feature can be found at the following URL: http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6642/prod_white_paper0900aecd804fa16a.html

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.
  
  

  Cisco IOS Software

  Each row of the following Cisco IOS Software table corresponds to a Cisco IOS Software train. If a particular train is vulnerable, the earliest releases that contain the fix are listed in the First Fixed Release column. The First Fixed Release for All Advisories in the March 2012 Bundled Publication column lists the earliest possible releases that correct all the published vulnerabilities in the Cisco IOS Software Security Advisory bundled publication. Cisco recommends upgrading to the latest available release, where possible.

  The Cisco IOS Software Checker allows customers to search for Cisco Security Advisories that address specific Cisco IOS Software releases. This tool is available on the Cisco Security (SIO) portal at https://sec.cloudapps.cisco.com/security/center/selectIOSVersion.x

  Major Release	Availability of Repaired Releases
  Affected 12.0-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  There are no affected 12.0 based releases
  Affected 12.2-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  12.2	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2B	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2BC	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2BW	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2BX	Not vulnerable	Vulnerable; First fixed in Release 12.2SB
  12.2BY	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2BZ	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2CX	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2CY	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2CZ	Not vulnerable	Vulnerable; First fixed in Release 12.0S
  12.2DA	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2DD	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2DX	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2EU	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2EW	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2EWA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2EX	Vulnerable; First fixed in Release 15.0SE Releases up to and including 12.2(55)EX3 are not vulnerable.	Vulnerable; First fixed in Release 15.0SE
  12.2EY	12.2(58)EY2	12.2(52)EY4
  12.2EZ	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2FX	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2FY	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2FZ	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2IRA	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2IRB	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2IRC	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2IRD	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2IRE	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2IRF	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2IRG	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IRH	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXB	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXC	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXD	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXE	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXF	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXG	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2IXH	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2JA	Not vulnerable	Not vulnerable
  12.2JK	Not vulnerable	Not vulnerable
  12.2MB	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2MC	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2MRA	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2MRB	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2S	Not vulnerable	Releases prior to 12.2(30)S are vulnerable; Releases 12.2(30)S and later are not vulnerable. First fixed in Release 12.0S
  12.2SB	Not vulnerable	12.2(33)SB12
  12.2SBC	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2SCA	Not vulnerable	Vulnerable; First fixed in Release 12.2SCE
  12.2SCB	Not vulnerable	Vulnerable; First fixed in Release 12.2SCE
  12.2SCC	Not vulnerable	Vulnerable; First fixed in Release 12.2SCE
  12.2SCD	Not vulnerable	Vulnerable; First fixed in Release 12.2SCE
  12.2SCE	Not vulnerable	12.2(33)SCE6
  12.2SCF	Not vulnerable	12.2(33)SCF2
  12.2SE	Vulnerable; First fixed in Release 15.0SE Releases up to and including 12.2(58)SE1 are not vulnerable.	12.2(55)SE5 *
  12.2SEA	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SEB	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SEC	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SED	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SEE	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SEF	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SEG	Not vulnerable	Vulnerable; First fixed in Release 15.0SE
  12.2SG	Not vulnerable	12.2(53)SG7; Available on 07-MAY-12
  12.2SGA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SL	Not vulnerable	Not vulnerable
  12.2SM	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SO	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SQ	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SRA	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2SRB	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2SRC	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2SRD	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2SRE	Not vulnerable	12.2(33)SRE6
  12.2STE	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SU	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2SV	Not vulnerable	Releases up to and including 12.2(18)SV2 are not vulnerable.
  12.2SVA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SVC	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SVD	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SVE	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SW	Not vulnerable	Vulnerable; First fixed in Release 12.4T
  12.2SX	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXB	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXD	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXE	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXF	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXH	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2SXI	Not vulnerable	12.2(33)SXI9
  12.2SXJ	Not vulnerable	12.2(33)SXJ2
  12.2SY	Not vulnerable	12.2(50)SY2; Available on 11-JUN-12
  12.2SZ	Not vulnerable	Vulnerable; First fixed in Release 12.0S
  12.2T	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2TPC	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2XA	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XB	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XC	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XD	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XE	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XF	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XG	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XH	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XI	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XJ	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XK	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XL	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XM	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XNA	Please see Cisco IOS-XE Software Availability	Please see Cisco IOS-XE Software Availability
  12.2XNB	Please see Cisco IOS-XE Software Availability	Please see Cisco IOS-XE Software Availability
  12.2XNC	Please see Cisco IOS-XE Software Availability	Please see Cisco IOS-XE Software Availability
  12.2XND	Please see Cisco IOS-XE Software Availability	Please see Cisco IOS-XE Software Availability
  12.2XNE	Please see Cisco IOS-XE Software Availability	Please see Cisco IOS-XE Software Availability
  12.2XNF	Please see Cisco IOS-XE Software Availability	Please see Cisco IOS-XE Software Availability
  12.2XO	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2XQ	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XR	Not vulnerable	Releases prior to 12.2(15)XR are vulnerable; Releases 12.2(15)XR and later are not vulnerable. First fixed in Release 15.0M
  12.2XS	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XT	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XU	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XV	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2XW	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2YA	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2YC	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YD	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YE	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YK	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YO	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YP	Not vulnerable	Vulnerable; First fixed in Release 15.0M Releases up to and including 12.2(8)YP are not vulnerable.
  12.2YT	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YW	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YX	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YY	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2YZ	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZB	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZC	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZD	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZE	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2ZH	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.2ZJ	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZP	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZU	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZX	Not vulnerable	Vulnerable; First fixed in Release 12.2SRE
  12.2ZY	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.2ZYA	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  Affected 12.3-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  There are no affected 12.3 based releases
  Affected 12.4-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  12.4	Releases 12.4(13d) and prior are not vulnerable; first fixed in 12.4(25f)	Vulnerable; First fixed in Release 15.0M
  12.4GC	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JA	12.4(23c)JA4 12.4(25e)JA	12.4(23c)JA4 12.4(25e)JA
  12.4JAX	Vulnerable; First fixed in Release 12.4JA	Vulnerable; First fixed in Release 12.4JA
  12.4JDA	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JDC	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JDD	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JDE	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JHA	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JHB	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JHC	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JK	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JL	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4JX	Vulnerable; First fixed in Release 12.4JA Releases up to and including 12.4(3g)JX2 are not vulnerable.	Vulnerable; First fixed in Release 12.4JA
  12.4JY	Vulnerable; First fixed in Release 12.4JA	Vulnerable; First fixed in Release 12.4JA
  12.4JZ	Vulnerable; First fixed in Release 12.4JA	Vulnerable; First fixed in Release 12.4JA
  12.4MD	12.4(22)MD3; Available on 30-MAR-12	12.4(22)MD3; Available on 30-MAR-12
  12.4MDA	12.4(24)MDA11	12.4(24)MDA11
  12.4MDB	12.4(24)MDB5a	12.4(24)MDB5a
  12.4MDC	Not vulnerable	Not vulnerable
  12.4MR	Releases up to and including 12.4(16)MR1 are not vulnerable.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4MRA	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4MRB	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M
  12.4SW	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4T	12.4(15)T16 12.4(24)T6	12.4(15)T17 12.4(24)T7
  12.4XA	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XB	Not vulnerable	Vulnerable; First fixed in Release 12.4T
  12.4XC	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XD	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XE	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XF	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XG	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XJ	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XK	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XL	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XM	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XN	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XP	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XQ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M
  12.4XR	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 12.4T
  12.4XT	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XV	Not vulnerable	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4XW	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XY	Not vulnerable	Vulnerable; First fixed in Release 15.0M
  12.4XZ	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M
  12.4YA	Vulnerable; First fixed in Release 12.4T	Vulnerable; First fixed in Release 15.0M
  12.4YB	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4YD	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  12.4YE	12.4(24)YE3d	12.4(24)YE3d
  12.4YG	12.4(24)YG4	12.4(24)YG4
  Affected 15.0-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  15.0M	15.0(1)M7	15.0(1)M8
  15.0MR	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.0MRA	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.0S	15.0(1)S5 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	15.0(1)S5 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.0SA	Not vulnerable	Not vulnerable
  15.0SE	15.0(1)SE1 15.0(2)SE; Available on 06-AUG-12	15.0(1)SE1
  15.0SG	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS-XE Software Availability	15.0(2)SG2 Cisco IOS XE devices: Please see Cisco IOS-XE Software Availability
  15.0SY	Not vulnerable	15.0(1)SY1
  15.0XA	Vulnerable; First fixed in Release 15.1T	Vulnerable; First fixed in Release 15.1T
  15.0XO	Cisco IOS XE devices: Please see Cisco IOS-XE Software Availability	Cisco IOS XE devices: Please see Cisco IOS-XE Software Availability
  Affected 15.1-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  15.1EY	15.1(2)EY1a	15.1(2)EY2
  15.1GC	15.1(2)GC2	15.1(2)GC2
  15.1M	15.1(4)M2	15.1(4)M4; Available on 30-MAR-12
  15.1MR	15.1(1)MR3	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1S	15.1(3)S2 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	15.1(3)S2 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.1SG	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.1SNG	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.	Vulnerable; contact your support organization per the instructions in Obtaining Fixed Software section of this advisory.
  15.1SNH	Not vulnerable	Not vulnerable
  15.1T	15.1(1)T4 15.1(2)T5; Available on 27-APR-12 15.1(3)T3	15.1(3)T3
  15.1XB	Vulnerable; First fixed in Release 15.1T	Vulnerable; First fixed in Release 15.1T
  Affected 15.2-Based Releases	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  15.2GC	15.2(1)GC1	15.2(1)GC2
  15.2S	Not vulnerable Cisco IOS XE devices: Please see Cisco IOS XE Software Availability	15.2(1)S1 Cisco IOS XE devices: Please see Cisco IOS XE Software Availability
  15.2T	15.2(1)T2 15.2(2)T 15.2(2)T1	15.2(1)T2 15.2(2)T1 15.2(3)T; Available on 30-MAR-12

  
  * Cisco Catalyst 3550 Series Switches support the Internet Key Exchange (IKE) feature and are vulnerable to Cisco bug ID CSCts38429 when the devices are running Layer 3 images; however, this product reached the End of Software Maintenance milestone.  Cisco 3550 Series SMI Switches that are running Layer 2 images do not support IKE and are not vulnerable.  No other Cisco devices that run 12.2SE-based software are vulnerable.
  
  

  Cisco IOS XE Software

  Cisco IOS XE Software is affected by the vulnerability that is disclosed in this document.

  
  

  Cisco IOS XE Software Release	First Fixed Release	First Fixed Release for All Advisories in the March 2012 Cisco IOS Software Security Advisory Bundled Publication
  2.1.x	Not vulnerable	Vulnerable; migrate to 3.4.2S or later.
  2.2.x	Not vulnerable	Vulnerable; migrate to 3.4.2S or later.
  2.3.x	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  2.4.x	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  2.5.x	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  2.6.x	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  3.1.xS	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  3.2.xSG	Not Vulnerable	Vulnerable; migrate to 3.2.2SG or later.
  3.2.xS	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  3.2.xSG	Not Vulnerable	3.2.2SG
  3.3.xS	Vulnerable; migrate to 3.4.2S or later.	Vulnerable; migrate to 3.4.2S or later.
  3.3.xSG	Not Vulnerable	Not Vulnerable
  3.4.xS	3.4.2S	3.4.2S
  3.5.xS	Not vulnerable	3.5.1S
  3.6.xS	Not vulnerable	Not vulnerable

  
  For a mapping of Cisco IOS XE Software releases to Cisco IOS Software releases, refer to Cisco IOS XE 2 Release Notes, Cisco IOS XE 3S Release Notes, and Cisco IOS XE 3SG Release Notes.

  Cisco IOS XR Software

  Cisco IOS XR Software is not affected by any of the vulnerabilities disclosed in the March 2012 Cisco IOS Software Security Advisory Bundled Publication.

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.

  This vulnerability was reported to Cisco by a customer.

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20120328-ssh

Revision History

• Revision 1.0

  2012-March-28

  Initial public release

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