[6bone] Fwd: Cisco Security Advisory: Multiple Crafted IPv6 Packets Cause Reload

Hank Nussbacher hank at mail.iucc.ac.il
Wed Jan 26 08:06:39 PST 2005


Ugh.  -Hank


>-----BEGIN PGP SIGNED MESSAGE-----
>Hash: SHA1
>
>Cisco Security Advisory: Multiple Crafted IPv6 Packets Cause Reload
>
>Revision 1.0
>
>For Public Release 2005 January 26 1600 UTC (GMT)
>
>- --------------------------------------------------------------------------
>
>Contents
>
>     Summary
>     Affected Products
>     Details
>     Impact
>     Software Versions and Fixes
>     Obtaining Fixed Software
>     Workarounds
>     Exploitation and Public Announcements
>     Status of This Notice: FINAL
>     Distribution
>     Revision History
>     Cisco Security Procedures
>
>- --------------------------------------------------------------------------
>
>Summary
>=======
>
>Cisco Internetwork Operating System (IOS) Software is vulnerable to a Denial
>of Service (DoS) attack from crafted IPv6 packets when the device has been
>configured to process IPv6 traffic. This vulnerability requires multiple
>crafted packets to be sent to the device which may result in a reload upon
>successful exploitation.
>
>Cisco has made free software available to address this vulnerability.
>
>There are workarounds available to mitigate the effects.
>
>This issue is tracked by CERT/CC VU#472582
>
>This advisory is available at 
>http://www.cisco.com/warp/public/707/cisco-sa-20050126-ipv6.shtml.
>
>Affected Products
>=================
>
>Vulnerable Products
>
>Only the Cisco devices running IOS and configured for IPv6 are affected. A
>router will display all IPv6 enabled interfaces with the show ipv6 interface
>command.
>
>An empty output or an error message will be displayed if IPv6 is disabled or
>unsupported on the system. In this case the system is not vulnerable.
>
>Sample output of show ipv6 interface command is shown below for a system
>configured for IPv6.
>
>       Router#show ipv6 interface
>       Serial1/0 is up, line protocol is up
>         IPv6 is enabled, link-local address is FE80::A8BB:CCFF:FE00:D200
>         Global unicast address(es):
>           2001:1:33::3, subnet is 2001:1:33::/64 [TENTATIVE]
>         Joined group address(es):
>           FF02::1
>           FF02::1:FF00:3
>           FF02::1:FF00:D200
>         MTU is 1500 bytes
>         ICMP error messages limited to one every 100 milliseconds
>         ICMP redirects are enabled
>         ND DAD is enabled, number of DAD attempts: 1
>         ND reachable time is 30000 milliseconds
>       Router#
>
>
>A router that has IPv6 enabled on a physical or logical interface is 
>vulnerable
>to this issue even if ipv6 unicast-routing is globally disabled. The show ipv6
>interface command can be used to determine whether IPv6 is enabled on any
>interface.
>
>Products Confirmed Not Vulnerable
>
>   * Products that are not running Cisco IOS are not affected.
>   * Products running any version of Cisco IOS that do not have IPv6 
> configured
>     interfaces are not vulnerable.
>
>No other Cisco products are currently known to be affected by these
>vulnerabilities.
>
>Details
>=======
>
>IPv6 is the "Internet Protocol Version 6", designed by the Internet 
>Engineering
>Task Force (IETF) to replace the current version Internet Protocol, IP Version
>4 (IPv4).
>
>A vulnerability exists in the processing of IPv6 packets that can be exploited
>to cause the reload of a system. Crafted packets received on logical 
>interfaces
>(that is, tunnels including 6to4 tunnels) as well as physical interfaces can
>trigger this vulnerability.
>
>Multiple crafted IPv6 packets need to be sent to exploit this vulnerability.
>Such crafted packets can be sent remotely.
>
>This issue is documented in Cisco bug ID CSCed40933 ( registered customers
>only) .
>
>Impact
>======
>
>Successful exploitation of this vulnerability results in a reload of the
>device. Repeated exploitation could result in a sustained DoS attack.
>
>Software Versions and Fixes
>===========================
>
>+-----------------------------------------------------+
>|   Major    |   Availability of Repaired Releases    |
>|  Release   |                                        |
>|------------+----------------------------------------|
>| Affected   |             |         |             |  |
>| 12.0-Based | Rebuild     | Interim | Maintenance |  |
>| Release    |             |         |             |  |
>|------------+-------------+---------+-------------+--|
>|            | 12.0(23)S   |         |             |  |
>|            | and before  |         |             |  |
>|            | are not     |         |             |  |
>|            | vulnerable. |         |             |  |
>|            |-------------+---------+-------------+--|
>|            | 12.0(24)S6  |         |             |  |
>|12.0S       |-------------+---------+-------------+--|
>|            | 12.0(25)S3  |         |             |  |
>|            |-------------+---------+-------------+--|
>|            | 12.0(26)S2  |         |             |  |
>|            |-------------+---------+-------------+--|
>|            | 12.0(27)S1  |         |             |  |
>|            |-------------+---------+-------------+--|
>|            |             |         | 12.0(28)S   |  |
>|------------+-------------+---------+-------------+--|
>| 12.0SX     | 12.0(25)SX8 |         |             |  |
>|------------+-------------------------------------+--|
>| 12.0SZ     | 12.0(27)SZ                          |  |
>|------------+-------------------------------------+--|
>| Affected   |             |         |             |  |
>| 12.2-Based | Rebuild     | Interim | Maintenance |  |
>| Release    |             |         |             |  |
>|------------+-------------------------------------+--|
>|            | 12.2(2)B - 12.2(4)B7 Migrate to     |  |
>|            | 12.2(13)T14 or later                |  |
>|12.2B       |-------------------------------------+--|
>|            | 12.2(4)B8 AND FWD Migrate to 12.3   |  |
>|            | (7)T or later                       |  |
>|------------+-------------------------------------+--|
>| 12.2BC     | Migrate to 12.3(9a)BC               |  |
>|------------+-------------------------------------+--|
>| 12.2BX     | Migrate to 12.3(7)XI1               |  |
>|------------+-------------------------------------+--|
>| 12.2BZ     | Migrate to 12.3(7)XI1               |  |
>|------------+-------------------------------------+--|
>| 12.2CX     | No plan.                            |  |
>|------------+-------------------------------------+--|
>| 12.2CZ     | No plan.                            |  |
>|------------+-------------------------------------+--|
>| 12.2EW     | 12.2(18)EW1                         |  |
>|------------+-------------------------------------+--|
>| 12.2EWA    |             |         | 12.2(20)EWA |  |
>|------------+-------------+---------+-------------+--|
>| 12.2JK     | 12.2(15)JK2 |         |             |  |
>|------------+-------------------------------------+--|
>| 12.2MC     | Migrate to 12.3(11)T                |  |
>|------------+-------------------------------------+--|
>|            | 12.2(14)S9  |         |             |  |
>|            |-------------+---------+-------------+--|
>|            | 12.2(18)S5  |         |             |  |
>|            |-------------+---------+-------------+--|
>| 12.2S      | 12.2(20)S3  |         |             |  |
>|            |-------------+---------+-------------+--|
>|            | 12.2(22)S1  |         |             |  |
>|            |-------------+---------+-------------+--|
>|            |             |         | 12.2(25)S   |  |
>|------------+-------------------------------------+--|
>| 12.2SE     | 12.2(25)SE                          |  |
>|------------+-------------------------------------+--|
>| 12.2SU     | 12.2(14)SU1 |         |             |  |
>|------------+-------------------------------------+--|
>| 12.2SV     | 12.2(23)SV                          |  |
>|------------+-------------------------------------+--|
>| 12.2SW     | 12.2(23)SW                          |  |
>|------------+-------------------------------------+--|
>| 12.2SX     | Migrate to 12.2(17d)SXB2 or later   |  |
>|------------+-------------------------------------+--|
>| 12.2SXA    | Migrate to 12.2(17d)SXB1 or later   |  |
>|------------+-------------------------------------+--|
>| 12.2SXB    | 12.2(17d)   |         |             |  |
>|            | SXB1        |         |             |  |
>|------------+-------------+---------+-------------+--|
>| 12.2SXD    |             |         | 12.2(18)SXD |  |
>|------------+-------------------------------------+--|
>| 12.2SY     | Migrate to 12.2(17d)SXB2 or later   |  |
>|------------+-------------------------------------+--|
>| 12.2SZ     | Migrate to 12.2(20)S4               |  |
>|------------+-------------------------------------+--|
>|            | 12.2(13)T14 |         |             |  |
>|12.2T       |-------------+---------+-------------+--|
>|            | 12.2(15)T12 |         |             |  |
>|------------+-------------------------------------+--|
>| 12.2YT     | Migrate to 12.2(15)T13 or later     |  |
>|------------+-------------------------------------+--|
>| 12.2YU     | Migrate to 12.3(4)T6 or later       |  |
>|------------+-------------------------------------+--|
>| 12.2YV     | Migrate to 12.3(4)T6 or later       |  |
>|------------+-------------------------------------+--|
>| 12.2YZ     | Migrate to 12.2(20)S4 or later      |  |
>|------------+-------------------------------------+--|
>| 12.2ZC     | Migrate to 12.3T or later           |  |
>|------------+-------------------------------------+--|
>| 12.2ZD     | Migrate to 12.3 or later            |  |
>|------------+-------------------------------------+--|
>| 12.2ZE     | Migrate to 12.3 or later            |  |
>|------------+-------------------------------------+--|
>| 12.2ZF     | Migrate to 12.3(4)T6 or later       |  |
>|------------+-------------------------------------+--|
>| 12.2ZG     | Migrate to 12.3(4)T6 or later       |  |
>|------------+-------------------------------------+--|
>| 12.2ZH     | Migrate to 12.3(4)T6 or later       |  |
>|------------+-------------------------------------+--|
>| 12.2ZI     | Migrate to 12.2(18)S or later       |  |
>|------------+-------------------------------------+--|
>| 12.2ZJ     | Migrate to 12.3 or later            |  |
>|------------+-------------------------------------+--|
>| 12.2ZL     | Migrate to 12.3(7)T or later        |  |
>|------------+-------------------------------------+--|
>| 12.2ZN     | Migrate to 12.3(2)T6 or later       |  |
>|------------+-------------------------------------+--|
>| 12.2ZO     | Migrate to 12.2(15)T12 or later     |  |
>|------------+-------------------------------------+--|
>| 12.2ZP     | Migrate to 12.3(8)XY or later       |  |
>|------------+-------------------------------------+--|
>| Affected   |             |         |             |  |
>| 12.3-Based | Rebuild     | Interim | Maintenance |  |
>| Release    |             |         |             |  |
>|------------+-------------+---------+-------------+--|
>|            | 12.3(3f)    |         |             |  |
>|            |-------------+---------+-------------+--|
>|            | 12.3(5c)    |         |             |  |
>|12.3        |-------------+---------+-------------+--|
>|            | 12.3(6a)    |         |             |  |
>|            |-------------+---------+-------------+--|
>|            |             |         | 12.3(9)     |  |
>|------------+-------------+---------+-------------+--|
>| 12.3BC     |             |         | 12.3(9a)BC  |  |
>|------------+-------------+---------+-------------+--|
>| 12.3B      | 12.3(5a)B2  |         |             |  |
>|------------+-------------------------------------+--|
>| 12.3BW     | Migrate to 12.3(5a)B2 or later      |  |
>|------------+-------------------------------------+--|
>| 12.3JA     |             |         | 12.3(2)JA   |  |
>|------------+-------------+---------+-------------+--|
>|            | 12.3(2)T6   |         |             |  |
>|            |-------------+---------+-------------+--|
>| 12.3T      | 12.3(4)T6   |         |             |  |
>|            |-------------+---------+-------------+--|
>|            |             |         | 12.3(7)T    |  |
>|------------+-------------------------------------+--|
>| 12.3XA     | Migrate to 12.3(7)T or later        |  |
>|------------+-------------------------------------+--|
>| 12.3XB     | Migrate to 12.3(8)T or later        |  |
>|------------+-------------------------------------+--|
>| 12.3XC     | Migrate 12.3(2)XC3 or later         |  |
>|------------+-------------------------------------+--|
>| 12.3XD     | 12.3(4)XD4  |         |             |  |
>|------------+-------------------------------------+--|
>| 12.3XE     | 12.3(2)XE1                          |  |
>|------------+-------------------------------------+--|
>| 12.3XF     | Migrate to 12.3(11)T or later       |  |
>|------------+-------------------------------------+--|
>| 12.3XG     | 12.3(4)XG2  |         |             |  |
>|------------+-------------------------------------+--|
>| 12.3XH     | Migrate to 12.3(11)T or later       |  |
>|------------+-------------------------------------+--|
>| 12.3XI     |             |         | 12.3(7)XI   |  |
>|------------+-------------------------------------+--|
>| 12.3XJ     | 12.3(7)XJ                           |  |
>|------------+-------------------------------------+--|
>| 12.3XK     | 12.3(4)XK1  |         |             |  |
>|------------+-------------+---------+-------------+--|
>| 12.3XL     |             |         | 12.3(7)XL   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3XM     |             |         | 12.3(7)XM   |  |
>|------------+-------------------------------------+--|
>| 12.3XN     | Migrate to 12.3(14)T or later       |  |
>|------------+-------------------------------------+--|
>| 12.3XQ     | 12.3(4)XQ                           |  |
>|------------+-------------------------------------+--|
>| 12.3XR     |             |         | 12.3(7)XR   |  |
>|------------+-------------------------------------+--|
>| 12.3XS     | 12.3(7)XS                           |  |
>|------------+-------------------------------------+--|
>| 12.3XT     | 12.3(2)XT                           |  |
>|------------+-------------------------------------+--|
>| 12.3XU     | 12.3(8)XU                           |  |
>|------------+-------------------------------------+--|
>| 12.3XX     |             |         | 12.3(8)XX   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3XW     |             |         | 12.3(8)XW   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3XY     |             |         | 12.3(8)XY   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3XZ     |             |         | 12.3(2)XZ   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3YA     |             |         | 12.3(8)YA   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3YD     |             |         | 12.3(8)YD   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3YE     |             |         | 12.3(4)YE   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3YF     |             |         | 12.3(11)YF  |  |
>|------------+-------------+---------+-------------+--|
>| 12.3YG     |             |         | 12.3(8)YG   |  |
>|------------+-------------+---------+-------------+--|
>| 12.3YH     |             |         | 12.3(8)YH   |  |
>+-----------------------------------------------------+
>
>When considering software upgrades, please also consult 
>http://www.cisco.com/en
>/US/products/products_security_advisories_listing.html and any subsequent
>advisories to determine exposure and a complete upgrade solution.
>
>In all cases, customers should exercise caution to be certain the devices 
>to be
>upgraded contain sufficient memory and that current hardware and software
>configurations will continue to be supported properly by the new release. If
>the information is not clear, contact the Cisco Technical Assistance Center
>(TAC) for assistance.
>
>Obtaining Fixed Software
>========================
>
>Customers with Service Contracts
>
>Customers with contracts should obtain upgraded software through their regular
>update channels. For most customers, this means that upgrades should be
>obtained through the Software Center on Cisco's worldwide website at http://
>www.cisco.com.
>
>Customers using Third-party Support Organizations
>
>Customers whose Cisco products are provided or maintained through prior or
>existing agreement with third-party support organizations such as Cisco
>Partners, authorized resellers, or service providers should contact that
>support organization for assistance with the upgrade, which should be free of
>charge.
>
>Customers without Service Contracts
>
>Customers who purchase direct from Cisco but who do not hold a Cisco service
>contract and customers who purchase through third-party vendors but are
>unsuccessful at obtaining fixed software through their point of sale 
>should get
>their upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC
>contacts are as follows.
>
>   * +1 800 553 2447 (toll free from within North America)
>   * +1 408 526 7209 (toll call from anywhere in the world)
>   * e-mail: tac at cisco.com
>
>Please have your product serial number available and give the URL of this
>notice as evidence of your entitlement to a free upgrade. Free upgrades for
>non-contract customers must be requested through the TAC.
>
>Please do not contact either "psirt at cisco.com" or "security-alert at cisco.com"
>for software upgrades.
>
>See http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for additional
>TAC contact information, including special localized telephone numbers and
>instructions and e-mail addresses for use in various languages.
>
>Customers may only install and expect support for the feature sets they have
>purchased. By installing, downloading, accessing or otherwise using such
>software upgrades, customers agree to be bound by the terms of Cisco's 
>software
>license terms found at http://www.cisco.com/public/sw-license-agreement.html,
>or as otherwise set forth at Cisco.com Downloads at 
>http://www.cisco.com/public
>/sw-center/sw-usingswc.shtml.
>
>Workarounds
>===========
>
>The effectiveness of any workaround is dependent on specific customer
>situations such as product mix, network topology, traffic behavior, and
>organizational mission. Due to the variety of affected products and releases,
>customers should consult with their service provider or support 
>organization to
>ensure any applied workaround is the most appropriate for use in the intended
>network before it is deployed.
>
>Although it is often difficult to block traffic transiting your network, it is
>possible to identify traffic which should never be allowed to target your
>infrastructure devices and block that traffic at the border of your network.
>Infrastructure access control lists (ACLs) 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 white
>paper entitled "Protecting Your Core: Infrastructure Protection Access Control
>Lists", available at http://www.cisco.com/warp/public/707/iacl.html, presents
>guidelines and recommended deployment techniques for infrastructure protection
>ACLs. Exceptions would include any devices which have a legitimate reason to
>access your infrastructure (for example, BGP peers, DNS servers, and so on).
>All other traffic must be able to traverse your network without terminating on
>any of your devices.
>
>Exploitation and Public Announcements
>=====================================
>
>The Cisco PSIRT is not aware of any public announcements or malicious use of
>the vulnerability described in this advisory.
>
>Status of This Notice: FINAL
>============================
>
>THIS ADVISORY IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF
>GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF
>THE INFORMATION ON THE ADVISORY OR MATERIALS LINKED FROM THE ADVISORY IS AT
>YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS NOTICE AT ANY
>TIME.
>
>A stand-alone copy or paraphrase of the text of this security advisory 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 will be posted on Cisco's worldwide website at http://
>www.cisco.com/warp/public/707/cisco-sa-20050126-ipv6.shtml.
>
>In addition to worldwide web posting, a text version of this notice is
>clear-signed with the Cisco PSIRT PGP key and is posted to the following 
>e-mail
>and Usenet news recipients.
>
>   * cust-security-announce at cisco.com
>   * first-teams at first.org (includes CERT/CC)
>   * bugtraq at securityfocus.com
>   * vulnwatch at vulnwatch.org
>   * cisco at spot.colorado.edu
>   * cisco-nsp at puck.nether.net
>   * full-disclosure at lists.netsys.com
>   * comp.dcom.sys.cisco at newsgate.cisco.com
>   * Various internal Cisco mailing lists
>
>Future updates of this advisory, if any, will be placed on Cisco's worldwide
>website, but may or may not be actively announced on mailing lists or
>newsgroups. Users concerned about this problem are encouraged to check the
>above URL for any updates.
>
>Revision History
>================
>
>+---------------------------------------------+
>| Revision | 2005-January-26 | Initial public |
>| 1.0      |                 | release.       |
>+---------------------------------------------+
>
>Cisco Security Procedures
>=========================
>
>Complete information on reporting security vulnerabilities in Cisco products,
>obtaining assistance with security incidents, and registering to receive
>security information from Cisco, is available on Cisco's worldwide website at
>http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html
>. This includes instructions for press inquiries regarding Cisco security
>notices. All Cisco security advisories are available at 
>http://www.cisco.com/go
>/psirt.
>
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