On 22/01/2005 8:52 PM Darrell Kristof (CE CEN) wrote:

Has anyone heard about some carriers doing emergency maintenance tonight on Internet routers due to a code vulnerability? I'm trying to find out what vendor it involves and the details behind it. I understand it's still under NDA, but I'm sure someone out there knows more.

Perhaps due to the vulnerabilities mentioned below. Todd -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Vulnerability in Cisco IOS Embedded Call Processing Solutions Revision 1.0 For Public Release 2005 January 19 1500 UTC +---------------------------------------------------------------------- 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 release trains 12.1YD, 12.2T, 12.3 and 12.3T, when configured for the Cisco IOS Telephony Service (ITS), Cisco CallManager Express (CME) or Survivable Remote Site Telephony (SRST) may contain a vulnerability in processing certain malformed control protocol messages. A successful exploitation of this vulnerability may cause a reload of the device and could be exploited repeatedly to produce a Denial of Service (DoS). This advisory is available at http://www.cisco.com/warp/public/707/cisco-sa-20050119-itscme.shtml Cisco has made free software upgrades available to address this vulnerability for all affected customers. There are workarounds available to mitigate the effects of the vulnerability. This vulnerability is documented by Cisco bug ID CSCee08584. Affected Products ================= Vulnerable Products +------------------ This issue affects all Cisco devices running any unfixed version of Cisco IOS code that supports, and is configured for ITS, CME or SRST. A Cisco device running ITS or CME will have the following line in the configuration: telephony-service A Cisco device running SRST will have the following line in the configuration: call-manager-fallback To determine the software running on a Cisco product, log in to the device and issue the show version command to display the system banner. Cisco IOS Software will identify itself as "Internetwork Operating System Software" or simply "IOS." On the next line of output, the image name will be displayed between parentheses, followed by "Version" and the IOS release name. Other Cisco devices will not have the show version command or will give different output. The following example identifies a Cisco product running IOS release 12.0(3) with an installed image name of C2500-IS-L: Cisco Internetwork Operating System Software IOS (TM) 2500 Software (C2500-IS-L), Version 12.0(3), RELEASE SOFTWARE The release train label is "12.0". The next example shows a product running IOS release 12.3(6) with an image name of C2600-JS-MZ: Cisco Internetwork Operating System Software IOS (tm) C2600 Software (C2600-JS-MZ), Version 12.3(6), RELEASE SOFTWARE (fc1) Additional information about Cisco IOS release naming can be found at http://www.cisco.com/warp/public/620/1.html. Products Confirmed Not Vulnerable +-------------------------------- ITS, CME and SRST are IOS-only features. Devices that do not run IOS are not vulnerable. Details ======== More information about Cisco's IOS Telephony Service (ITS) and Cisco CallManager Express (CME) can be found here: http://www.cisco.com/en/US/products/sw/voicesw/ps4625/index.html More information on Cisco's Survivable Remote Site Telephony (SRST) can be found here: http://www.cisco.com/en/US/products/sw/voicesw/ps2169/index.html ITS, CME and SRST are features that allow a Cisco device running IOS to control IP Phones using the Skinny Call Control Protocol (SCCP). SCCP is the Cisco CallManager native signaling protocol. Certain malformed packets sent to the SCCP port on an IOS device configured for ITS, CME or SRST may cause the target device to reload. This issue is documented in Cisco bug ID CSCee08584. The following commands can be used to determine if ITS or CME are running. A device that does not have ITS or CME enabled will display: Router#show telephony-service telephony-service is not enabled A device that has ITS or CME enabled will show something similar to: Router#show telephony-service CONFIG (Version=3.0) ===================== Cisco CallManager Express ip source-address 192.168.1.1 port 2000 max-ephones 2 max-dn 2 max-conferences 8 max-redirect 5 time-format 12 date-format mm-dd-yy keepalive 30 timeout interdigit 10 timeout busy 10 timeout ringing 180 edit DN through Web: disabled. edit TIME through web: disabled. Log (table parameters): max-size: 150 retain-timer: 15 create cnf-files version-stamp Jan 01 2002 00:00:00 auto assign 1 to 2 local directory service: enabled. The following commands can be used to determine if SRST is running. A device that does not have SRST enabled will display: Router#show call-manager-fallback Call-manager fallback is not enabled A device that has SRST enabled will show something similar to: Router#show call-manager-fallback CONFIG ====== ip source-address 192.168.1.1 port 2000 max-ephones 2 max-dn 4 huntstop time-format 12 date-format mm-dd-yy keepalive 30 interdigit timeout 10 busy timeout 10 Limit number of DNs per phone: 7910: 34 7935: 34 7940: 34 7960: 34 Spoofed attacks are impractical since the attacker must pass all of the TCP/IP integrity checks first, including the initial sequence number and source TCP port number. Impact ====== Successful exploitation of the vulnerability may result in a device reload. Repeated exploitation could result in a Denial of Service (DoS) attack. Software Versions and Fixes =========================== Each row of the Cisco IOS software table (below) describes a release train and the platforms or products for which it is intended. If a given release train is vulnerable, then the earliest possible releases that contain the fix (the "First Fixed Release") and the anticipated date of availability for each are listed in the "Rebuild" and "Maintenance" columns. A device running a release in the given train that is earlier than the release in a specific column (less than the First Fixed Release) is known to be vulnerable. The release should be upgraded at least to the indicated release or a later version (greater than or equal to the First Fixed Release label). For further information on the terms "Rebuild" and "Maintenance" please consult the following URL: http://www.cisco.com/warp/public/620/1.html When considering software upgrades, please also consult http://www.cisco.com/en/US/products/products_security_advisories_listing.htm... 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 asssistance. +------------------------------------------+ | Major | Availability of Repaired | | Release | Releases | |------------+-----------------------------| | Affected | | | | 12.1-Based | Rebuild | Maintenance | | Release | | | |------------+-----------------------------| | 12.1YD | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.1YE | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.1YI | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | Affected | | | | 12.2-Based | Rebuild | Maintenance | | Release | | | |------------+-----------------------------| | 12.2B | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2BC | Migrate to 12.3(9)BC or | | | later | |------------+-----------------------------| | 12.2CZ | Migrate to 12.2(15)CZ1 | | | or later | |------------+-----------------------------| | 12.2JK | 12.2(15)JK2 | |------------+-----------------------------| | | 12.2(13) | | | | T14 | | |12.2T |------------+----------------| | | 12.2(15) | | | | T13 | | |------------+-----------------------------| | 12.2XB | Migrate to 12.3(9) or | | | later | |------------+-----------------------------| | 12.2XG | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2XM | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2XT | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2XU | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2XW | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2XZ | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YA | 12.2(4)YA8 | | |------------+-----------------------------| | 12.2YB | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YC | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YD | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2YF | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YG | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YH | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YJ | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2YL | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2YM | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2YN | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2YQ | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2YR | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2YS | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2ZK | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.2ZO | Migrate to 12.2(15)T13 | | | or later | |------------+-----------------------------| | 12.2ZP | Migrate to 12.3(4)XN2 or | | | later | |------------+-----------------------------| | Affected | | | | 12.3-Based | Rebuild | Maintenance | | Release | | | |------------+------------+----------------| | | 12.3(5d) | | | |------------+----------------| | 12.3 | 12.3(6c) | | | |------------+----------------| | | | 12.3(9) | |------------+------------+----------------| | | 12.3(2)T7 | | | |------------+----------------| | | 12.3(4)T6 | | |12.3T |------------+----------------| | | 12.3(7)T1 | | | |------------+----------------| | | | 12.3(8)T | |------------+-----------------------------| | 12.3XA | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.3XB | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.3XC | Migrate to 12.3(8)T or | | | later | |------------+-----------------------------| | 12.3XD | 12.3(4)XD3 | | |------------+------------+----------------| | 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)XJ2 | | |------------+------------+----------------| | 12.3XK | 12.3(4)XK1 | | |------------+------------+----------------| | 12.3XL | | 12.3(7)XL | |------------+-----------------------------| | 12.3XN | Contact Cisco TAC | |------------+-----------------------------| | | 12.3(4)XQ1 | | | | Release | | | 12.3XQ | date not | | | | yet | | | | determined | | +------------------------------------------+ 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 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@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@cisco.com" or "security-alert@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. Affected devices that must run ITS, CME or SRST are vulnerable, and there are not any specific configurations that can be used to protect them. Applying access lists on interfaces that should not accept ITS, CME or SRST traffic and putting firewalls in strategic locations may greatly reduce exposure until an upgrade can be performed. The IP Telephony Security in Depth SAFE paper at the URL below discusses a variety of best practices that should keep your voice network isolated from the Internet. These best practices may help to reduce the risk of exposure, although attacks from within the local network should always be considered a potential risk. http://www.cisco.com/en/US/netsol/ns340/ns394/ns171/ns128/networking_solutio... Using 'strict-match' +------------------- It is possible to restrict SCCP communications to the IP specified in the ip source-address configuration command by using the strict-match option. More information on this command can be found at the following URL: http://www.cisco.com/en/US/netsol/ns340/ns394/ns165/ns391/networking_solutio... Using Access Lists +----------------- Where possible, it is recommended to block SCCP traffic at the network edge with an Infrastructure Access Control List (iACL) or a Transit Access Control List (tACL). For more information on iACLs, refer to "Protecting Your Core: Infrastructure Protecton Access Control Lists": http://www.cisco.com/warp/public/707/iacl.html For more information on tACLs, refer to 'Transit Access Control Lists: Filtering at Your Edge": http://www.cisco.com/warp/public/707/tacl.html Below is an example of an access list to block SCCP traffic from anywhere but a permitted network. Note: In SRST deployments the SCCP packets are not addressed directly to the SRST device. The SCCP packets will be addressed to the call control devices (typically Cisco CallManager). In this example, the permitted telephony devices are on the 172.16.0.0/16 network and the SCCP port being used is the default, TCP port 2000. If the specific IP addresses of the telephony devices are known, then the access list can be made to restrict traffic from only those devices. !--- Permit access from any IP address in the 172.16.0.0/16 !--- to TCP port 2000. access-list 101 permit tcp 172.16.0.0 0.0.255.255 any eq 2000 !--- Deny all traffic to port 2000. access-list 101 deny tcp any any eq 2000 !--- Permit all other traffic. access-list 101 permit ip any any Using Control Plane Policing +--------------------------- The Control Plane Policing (CoPP) feature may be used to mitigate this vulnerability. In the following example SCCP traffic is permitted to and from the 192.168.10.0/24 subnet. All other TCP port 2000 traffic destined to the device is blocked. access-list 140 deny tcp 192.168.10.0 0.0.0.255 any eq 2000 access-list 140 deny tcp any 192.168.10.0 0.0.0.255 eq 2000 access-list 140 permit tcp any any eq 2000 access-list 140 deny ip any any class-map match-all sccp-class match access-group 140 policy-map control-plane-policy class sccp-class police 8000 1500 1500 conform-action drop exceed-action drop control-plane service-policy input control-plane-policy CoPP is available in IOS release trains 12.2S and 12.3T. Additional information on the configuration and use of the CoPP feature can be found at the following URL: http://www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_feature_guid... Exploitation and Public Announcements ===================================== The vulnerability described by CSCee08584 was originally reported to Cisco by SecureTest. 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-20050119-itscme.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@cisco.com * first-teams@first.org (includes CERT/CC) * bugtraq@securityfocus.com * vulnwatch@vulnwatch.org * cisco@spot.colorado.edu * cisco-voice@puck.nether.net * full-disclosure@lists.netsys.com * comp.dcom.sys.cisco@newsgate.cisco.com 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 | | Initial | | 1.0 | 2005-Jan-19 | Public | | | | 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.h.... This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at http://www.cisco.com/go/psirt. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (SunOS) iD8DBQFB7n24ezGozzK2tZARAumZAJ44GLqcYOm4jvjcy8HrsF3m4Z0hIQCcCwA9 90XZfoGYoUiSUH7BQzEdtRs= =zTtV -----END PGP SIGNATURE-----

One of my upstreams did so on the transit router we connect to. ----- Original Message ----- From: "Darrell Kristof (CE CEN)" <Darrell.Kristof@wholefoods.com> To: <nanog@merit.edu> Sent: Saturday, January 22, 2005 7:52 PM Subject: Emergency Internet Backbone Provider Maintenance Tonight All: Has anyone heard about some carriers doing emergency maintenance tonight on Internet routers due to a code vulnerability? I'm trying to find out what vendor it involves and the details behind it. I understand it's still under NDA, but I'm sure someone out there knows more. Thanks, - Darrell ====================================================================== Darrell Kristof, CISSP, CCNP, TICSA Network Manager/Team Leader Whole Foods Market, Corporate Offices

Has anyone heard about some carriers doing emergency maintenance tonight on Internet routers due to a code vulnerability? I'm trying to find out what vendor it involves and the details behind it. I understand it's still under NDA, but I'm sure someone out there knows more.

I doubt it's related, but the only thing I noticed is that sometime around 4am PST, twtelecom seems to have started blocking port 22 somewhere between 66.192.251.24 and 66.192.255.90, since I was in the middle of an ssh session when it dropped. Fortunately, I run a secondary ssh process, as well as have several alternate routes available to get around this. So I just forwarded the tcptraceroutes and other appropriate info to Cox (as this is from my cablemodem at home) since I don't want to really call twtelecom's noc at 4 in the morning.

I do not expect, that any carriet took this as an emergency - defect is quite harmless (DOS in the worst case, + no exploits known, + no any interest for anyone to do it, + VoIP gateways involved only...). Even if someone is doing maintanance, it can be noticed by VoIP network users only. Moreover, correct me if it was not defect in Cisco express call center (call center @ IOS) - I can not image carriers using this (it was designed for small businesses). Why to get simple, relatively harmless (require ugrade in next scheduled time, usually 1 - 3 weeks) defect as a terrible threat to everyone? Even BGP problem was much more dangerous (and no single case known since this, so it was not emergency as well).. ----- Original Message ----- From: "Darrell Kristof (CE CEN)" <Darrell.Kristof@wholefoods.com> To: <nanog@merit.edu> Sent: Saturday, January 22, 2005 7:52 PM Subject: Emergency Internet Backbone Provider Maintenance Tonight All: Has anyone heard about some carriers doing emergency maintenance tonight on Internet routers due to a code vulnerability? I'm trying to find out what vendor it involves and the details behind it. I understand it's still under NDA, but I'm sure someone out there knows more. Thanks, - Darrell ====================================================================== Darrell Kristof, CISSP, CCNP, TICSA Network Manager/Team Leader Whole Foods Market, Corporate Offices