Advisory ID: cisco-sa-20010614-nrp2-telnet
For Public Release 2001 June 14 15:00 UTC (GMT)
Vulnerability Scoring Details
Software Versions and Fixes
Obtaining Fixed Software
Exploitation and Public Announcements
Status of This Notice: Final
Cisco Security Procedures
The Cisco 6400 Access Concentrator Node Route Processor 2 (NRP2) module allows Telnet access when no password has been set. The correct response is to disallow any remote access to the module until the password has been set. This vulnerability may result in users gaining unintended access to secure systems.
This vulnerability is documented as Cisco bug ID CSCdt65960.
This advisory will be posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20010614-nrp2-telnet.
This section provides details on affected products.
Cisco 6400 NRP2 modules running Cisco IOS® release earlier than 12.1(05)DC01 are affected by this vulnerability.
To determine your software revision, type show version at the command line prompt.
Cisco 6400 NSP and Cisco 6400 NRP1 modules are not affected by this vulnerability. No other Cisco product is currently known to be affected by this vulnerability.
The Cisco 6400 Access Concentrator NRP2 module allows Telnet access when no password is set for the vtys on the NRP2. This vulnerability affects the Gigabit Ethernet, ATM and Serial interface on the NRP2. The correct response is to not allow any remote access to the module until the vty password has been set.
This vulnerability is documented as Cisco bug ID CSCdt65960, which requires a CCO account to view.
CVSS is a standards-based scoring method that conveys vulnerability severity and helps determine urgency and priority of response.
Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks.
Cisco has provided an FAQ to answer additional questions regarding CVSS at
Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at
A user can gain access to secure systems if the initial vtys have not had their password set.
This vulnerability can be eliminated by applying the workaround or by upgrading the IOS.
This vulnerability has been fixed in Cisco IOS release 12.1(05)DC01 or later.
Apply password to all the 32 vtys on the NRP2.
Enable Prompt> vty 0 31 password "the-password"
Cisco has made free software available to address this vulnerability for affected customers. 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/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.
Do not contact either "firstname.lastname@example.org" or "email@example.com" for software upgrades.
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 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 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 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)
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.
Refer to 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.
The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities described in this advisory.
This vulnerability was reported to Cisco by a Cisco customer.
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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.
This advisory will be posted on Cisco's worldwide website at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20010614-nrp2-telnet.
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.
firstname.lastname@example.org (includes CERT/CC)
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.
Initial public release.
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.