Cisco Security Advisory

Advisory ID: cisco-sa-20020410-solaris-bin-login

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20020410-solaris-bin-login

Revision 1.0

For Public Release 2002 April 10 16:00  UTC (GMT)

Summary

This advisory describes a vulnerability that affects Cisco products and applications that are installed on the Solaris operating system, and is based on the vulnerability of an common service within the Solaris operating system, not due to a defect of the Cisco product or application. A vulnerability in the "/bin/login" program was discovered that enables an attacker to execute arbitrary code under Solaris OS. This vulnerability was discovered and publicly announced by Internet Security Systems Inc. All Cisco products and applications that are installed on Solaris OS are considered vulnerable to the underlying operating system vulnerability, unless steps have been taken to disable access services such as "bin/login."

We are investigating other Solaris-based products.

This vulnerability can be mitigated in many cases (not all), by limiting interactive logins to trusted hosts using access control list (ACL) or other mechanisms such as firewalls.

This advisory is available at the http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20020410-solaris-bin-login.

Affected Products

All implementations of the "login" program (also known as "/bin/login" due to its location on the file system) derived from the SysV implementation are vulnerable to a buffer overflow. This vulnerability can be exploited to gain unauthorized access to a computer system without possessing legitimate credentials. The only prerequisite for exploiting this vulnerability is to have Telnet or other remote login access to the computer because there are multiple ways to access a computer remotely. Telnet, rlogin, rsh, SSH, and X term are the most commonly known methods. This vulnerability can be exploited locally and remotely.

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
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 .

By gaining unauthorized access an attacker can view and modify any part of the operating system possibly leading to a breach of confidentiality and integrity of the system.

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.

MGC and Related Products

• For the SC2200, the package CSCOh008.pkg release 1.0(8) contains the fix. The installation instruction is included within the package.
  
• For the products based on Solaris 2.6, the package CSCOh007.pkg release 1.0(7), or higher, contains the fix. The installation instruction is included within the package. This is applicable to the following products:
  - SC2200
  - VSC3000
  - PGW2200 PSTN Gateway
  - BAMS
  - VSPT
  

Both packages are available at http://www.cisco.com/pcgi-bin/tablebuild.pl/mgc-sol .

For all MGC and related products, you may also consult "Cisco Security Advisory: Hardening of Solaris OS for MGC" located at http://www.cisco.com/warp/public/707/Solaris-for-MGC-pub.shtml.

Cisco IDS

For IDS, release 3.0(5) is the first fixed release. The fixed software can be downloaded from http://www.cisco.com/pcgi-bin/tablebuild.pl/ids-appsens.

There is no workaround for MGC and related products.

For IDS, it is possible to mitigate the exposure by limiting hosts that can Telnet to IDS. This procedure is described at:

http://www.cisco.com/en/US/docs/net_mgmt/cisco_info_center_for_security_monitoring/3.5/roadmap/docguide.html.

In short, the user must login to the IDS machine as root, type sysconfig-sensor at the prompt, select option 5, and enter the hosts allowed to Telnet to the sensor.

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/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 either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades.

Customers with Service Contracts

Customers Using Third-Party Support Organizations

Customers Without Service Contracts

This vulnerability has been discovered by ISS Inc. and has been disclosed publicly. The advisories are published at:

• http://www.iss.net/security_center/alerts/advise105.php
  
• http://www.cert.org/advisories/CA-2001-34.html
  

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

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. CISCO EXPECTS TO UPDATE THIS DOCUMENT AS NEW INFORMATION BECOMES AVAILABLE.

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-20020410-solaris-bin-login.

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
  
• bugtraq@securityfocus.com
  
• first-teams@first.org (includes CERT/CC)
  
• cisco@spot.colorado.edu
  
• comp.dcom.sys.cisco
  
• firewalls@lists.gnac.com
  
• Various internal Cisco mailing lists
  

Future updates of this notice, if any, will be placed on Cisco's worldwide web server, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the URL given above for any updates.

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.