Cisco Security Advisory

Cisco ONS 15327, ONS 15454, ONS 15454 SDH, and ONS 15600 Vulnerabilities

Advisory ID: cisco-sa-20040219-ONS

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20040219-ONS

Revision 1.0

For Public Release 2004 February 19 17:00  UTC (GMT)


Summary

Multiple vulnerabilities exist in the Cisco ONS 15327 Edge Optical Transport Platform, the Cisco ONS 15454 Optical Transport Platform, the Cisco ONS 15454 SDH Multiplexer Platform, and the Cisco ONS 15600 Multiservice Switching Platform.

These vulnerabilities are documented as Cisco bug ID CSCec17308/CSCec19124(tftp), CSCec17406(port 1080), and CSCec66884/CSCec71157(SU access). There are workarounds available to mitigate the effects of these vulnerabilities.

This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20040219-ONS.

Affected Products

Vulnerable Products

  • Cisco ONS 15327 Edge Optical Transport Platform.
  • Cisco ONS 15454 Optical Transport Platform.
  • Cisco ONS 15454 SDH Multiplexer Platform.
  • Cisco ONS 15600 Multiservice Switching Platform.

Products Confirmed Not Vulnerable

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

Details

The affected Cisco ONS 15327, ONS 15454, ONS 15454 SDH, and ONS 15600 hardware is managed through the XTC, TCC+/TCC2, TCCi/TCC2, and TSC control cards respectively. These control cards are usually connected to a network isolated from the Internet and local to the customer's environment. This limits the exposure to the exploitation of the vulnerabilities from the Internet.

  • CSCec17308/CSCec19124(tftp)
    The TFTP service on UDP port 69 is enabled by default to allow both GET and PUT commands to be executed without any authentication. Using a TFTP client, it is possible to connect to the optical device and upload or retrieve ONS system files on the current active TCC in the /flash0 or /flash1 directories. It is not possible to upload or retrieve any user data files.
    Cisco bug ID CSCec17308 documents the issue on the Cisco ONS 15327, ONS 15454 and ONS 15454 SDH, and Cisco bug ID CSCec19124 documents the issue on the Cisco ONS 15600 hardware.
  • CSCec17406(port 1080)
    The Cisco ONS 15327, ONS 15454 and ONS 15454 SDH hardware is susceptible to an ACK Denial of Service (DoS) attack on TCP port 1080. TCP port 1080 is used by network management applications to communicate with the controller card. The controller card on the optical device will reset under such an attack.
    An ACK DoS attack is conducted by not sending the final ACK required for a 3-way TCP handshake to complete, and instead sending an invalid response to move the connection to an invalid TCP state.
    The Cisco ONS 15600 Multiservice Switching Platform is not affected by this vulnerability.
  • CSCec66884/CSCec71157(SU access)
    Telnet access to the underlying VxWorks operating system, by default, is restricted to Superusers only. Due to this vulnerability, a superuser whose account is locked out, disabled, or suspended is still able to login (Telnet) into the VxWorks shell, using their previously configured password.
    Cisco bug ID CSCec66884 documents the issue on the Cisco ONS 15327, ONS 15454 and ONS 15454 SDH, and Cisco bug ID CSCec71157 documents the issue on the Cisco ONS 15600 hardware.

The Internetworking Terms and Cisco Systems Acronyms online guides can be found at http://www.cisco.com/univercd/cc/td/doc/cisintwk/.

These vulnerabilities are documented in the Cisco Bug Toolkit ( registered customers only) as Cisco bug IDs CSCec17308/CSCec19124(tftp), CSCec17406(port 1080), and CSCec66884/CSCec71157(SU access). To access this tool, you must be a registered user and you must be logged in.

Vulnerability Scoring Details

Cisco has provided an FAQ to answer additional questions regarding CVSS at
http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html .

Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at
http://intellishield.cisco.com/security/alertmanager/cvss .

Impact

  • CSCec17308/CSCec19124(tftp) -- This vulnerability could be exploited to launch a DoS attack on the optical device if corrupt ONS system files were to be uploaded to the controller card.
  • CSCec17406(port 1080) -- This vulnerability could be exploited to launch a DoS attack on the optical device.
    The timing for the data channels traversing the switch is provided by the control cards.
    On the Cisco ONS 15454, ONS 15327, and ONS 15454 SDH hardware, whenever both the active and standby control cards are rebooting at the same time, the synchronous data channels traversing the switch drop traffic until the card reboots. Asynchronous data channels traversing the switch are not impacted. Manageability functions provided by the network element using the TCC+/TCC2, XTC, and TCCi/TCC2 control cards are not available until the control card reboots.
    On the Cisco ONS 15600 hardware, whenever both the active and standby control cards are rebooting at the same time, there is no impact to the data channels traversing the switch because the TSC does a software reset which does not impact the timing being provided by the TSC for the data channels.
    Manageability functions provided by the network element through the TSC control cards are not available until the control card reboots.
  • CSCec66884/CSCec71157(SU access) -- This vulnerability could be exploited to gain unauthorized access to the optical device.

Software Versions and Fixes

When considering software upgrades, also consult http://www.cisco.com/go/psirt 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) or your contracted maintenance provider for assistance.

  • CSCec17308/CSCec19124(tftp)
    Product
    Fixed Releases
    15327
    4.1(3) and later
    15454, 15454 SDH
    4.6(1) and later, 4.1(3) and later
    15600
    1.3(0) and later, 1.1(0) and later

  • CSCec17406(port 1080)
    Product
    Fixed Releases
    15327
    4.1(1) and later, 4.0(2) and later
    15454, 15454 SDH
    4.6(1) and later, 4.1(1) and later, 4.0(2) and later
    15600
    Not Affected

  • CSCec66884/CSCec71157(SU access)
    Product
    Fixed Releases
    15327
    4.1(3) and later
    15454, 15454 SDH
    4.6(1) and later, 4.1(3) and later
    15600
    1.1(1), 5.0 and later (when available)

    Cisco ONS Release 4.6(0) is not affected by these vulnerabilities. The recommended release to upgrade to is Cisco ONS release 4.6(1).

Upgrade procedures can be found as indicated below.


Workarounds

There are mitigation workarounds available for these vulnerabilities. The Cisco PSIRT recommends that affected users upgrade to a fixed software version of code.

  • CSCec17308/CSCec19124(tftp)
    Use access control lists on routers and firewalls that are installed in the network to allow only valid network management workstations to gain TFTP access to the XTC, TCC+/TCC2, TCCi/TCC2, or TSC control cards.
  • CSCec17406(port 1080)
    Use access control lists on routers and firewalls that are installed in the network to allow only valid network management workstations to gain TCP port 1080 access to the XTC, TCC+/TCC2, TCCi/TCC2, or TSC control cards.
  • CSCec66884/CSCec71157(SU access)
    Use access control lists on routers and firewalls that are installed in the network to allow only valid network management workstations to gain login (Telnet) access to the XTC, TCC+/TCC2, TCCi/TCC2, or TSC control cards.

Refer to http://www.cisco.com/en/US/tech/tk648/tk361/technologies_white_paper09186a00801a1a55.shtml for examples on how to apply access control lists (ACLs) on Cisco routers.

Obtaining Fixed Software

Cisco has released free software updates that address these vulnerabilities. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment.

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/en/US/docs/general/warranty/English/EU1KEN_.html , or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml .

Do not contact psirt@cisco.com or security-alert@cisco.com for software upgrades

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 agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers should contact that support organization for guidance and assistance with the appropriate course of action in regards to this advisory.

The effectiveness of any workaround or fix 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 or fix is the most appropriate for use in the intended network before it is deployed.

Customers Without Service Contracts

Customers who purchase direct from Cisco but do not hold a Cisco service contract, and customers who purchase through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should acquire 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@cisco.com

Customers should have their product serial number available and be prepared to give the URL of this notice as evidence of entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC.

Refer to http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, and instructions and e-mail addresses for use in various languages.

Exploitation and Public Announcements

The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory.

This vulnerability was reported to Cisco by internal testing.

Status of This Notice: Final

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.

A stand-alone copy or Paraphrase of the text of this document 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 is posted on Cisco's worldwide website at:

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20040219-ONS

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
  • bugtraq@securityfocus.com
  • vulnwatch@vulnwatch.org
  • cisco@spot.colorado.edu
  • cisco-nsp@puck.nether.net
  • full-disclosure@lists.grok.org.uk
  • 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 1.0

2004-February-19

Initial 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/web/about/security/psirt/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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