Summary
Affected Products
Details
Impact
Software Versions and Fixes
Workarounds
Obtaining Fixed Software
Exploitation and Public Announcements
Status of This Notice: INTERIM
Distribution
Revision History
Cisco Security Procedures
New vulnerabilities in the
OpenSSH
implementation
for SSH servers have been announced.
An affected network device, running an SSH server based on the OpenSSH implementation, may be vulnerable to a Denial of Service (DoS) attack when an exploit script is repeatedly executed against the same device. There are workarounds available to mitigate the effects of these vulnerabilities.
This advisory will be posted at http://www.cisco.com/warp/public/707/cisco-sa-20030917-openssh.shtml.
This section provides details on affected products.
The following products, have their SSH server implementation based on the OpenSSH code, and are affected by the OpenSSH vulnerabilities.
Cisco has not released code with SSH for the SN5420 storage router.
The following products, which incorporate a SSH server, have been confirmed to be not vulnerable to the OpenSSH vulnerabilities.
No other Cisco products are currently known to be affected by these vulnerabilities.
The buffer size or the number of channels in the fixed code is now correctly incremented only after a successful allocation where as initially they were being set before an allocation. Upon an allocation failure, which could be externally triggered, memory contents would be incorrectly erased by the cleanup process. This would result in a corruption of the memory which would eventually lead to a crash for the process using that memory.
Portable OpenSSH version (not OpenBSD version) 3.7p1 and 3.7.1p1 contain multiple vulnerabilities in the new PAM authentication code. These vulnerabilities are not known to affect any Cisco products.
Please note, the SSH server code under Cisco IOS has other vulnerabilities as documented by http://www.cisco.com/warp/public/707/ssh-packet-suite-vuln.shtml which may be triggered by the code written to exploit the OpenSHH vulnerabilities.
An affected device, running an SSH server based on the OpenSSH implementation, may be vulnerable to a DoS attack when an exploit script is repeatedly executed against the same device.
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.
The Cisco PSIRT recommends that affected users upgrade to a fixed software version of code as soon as it is available.
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 "psirt@cisco.com" or "security-alert@cisco.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.
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 malicious use of the vulnerabilities described in this advisory, at this time.
These vulnerabilities have also been documented by CERT/CC at
http://www.cert.org/advisories/CA-2003-24.html
.
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://www.cisco.com/warp/public/707/cisco-sa-20030917-openssh.shtml.
In addition to worldwide website posting, a text version of this advisory is clear-signed with the Cisco PSIRT PGP key having the fingerprint 8C82 5207 0CA9 ED40 1DD2 EE2A 7B31 A8CF 32B6 B590 and is posted to the following e-mail and Usenet news recipients:
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 1.6 |
2003-November-07 |
Added Cisco PGW 2200 Softswitch as a vulnerable product. Added 8.1(3) as a fixed release for CatOS. |
|
Revision 1.5 |
2003-September-27 |
Added not vulnerable to Portable OpenSSH version in the details section. Added ACNS and BTS10200 as vulnerable. Added 5.x as affected release for CSS11000. Updated fix information for NAM. |
|
Revision 1.4 |
2003-September-23 |
Added CatOS release schedule in Software Versions and Fixes. |
|
Revision 1.3 |
2003-September-19 |
Added Cisco Content Service CSS11000 Switch series and Cisco Network Analysis Modules (NAM) as being affected. |
|
Revision 1.2 |
2003-September-18 |
Added an additional workaround for the CatOS in the Workaround section. |
|
Revision 1.1 |
2003-September-18 |
Added CatOS versions, Cisco Secure Intrusion Detection System (NetRanger) appliance, and Cisco GSS 4480 Global Site Selector to the Affected Products section; and Cisco Secure Intrusion Detection System Catalyst Module (IDSM) to the not vulnerable list. Added Cisco Secure Intrusion Detection System (NetRanger) appliance, and Cisco GSS 4480 Global Site Selector to the Details section, and added Bug IDs for the products. Added Cisco Secure Intrusion Detection System (NetRanger) appliance to the Software Versions and Fixes section, and added upcoming fixes for the products. |
|
Revision 1.0 |
2003-September-17 |
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.
| Updated: Nov 07, 2003 | Document ID: 45322 |