openssh security, bug fix, and enhancement update (RHSA-2009-1287)

Original Release Date: September 14, 2009
Last Revised: October 18, 2010
Number: ASA-2009-406
Risk Level: Low
Advisory Version: 2.0
Advisory Status: Final

1. Overview:

OpenSSH is OpenBSD's SSH (Secure Shell) protocol implementation. These packages include the core files necessary for both the OpenSSH client and server.

A flaw was found in the SSH protocol. An attacker able to perform a man-in-the-middle attack may be able to obtain a portion of plain text from an arbitrary ciphertext block when a CBC mode cipher was used to encrypt SSH communication. This update helps mitigate this attack: OpenSSH clients and servers now prefer CTR mode ciphers to CBC mode, and the OpenSSH server now reads SSH packets up to their full possible length when corruption is detected, rather than reporting errors early, reducing the possibility of successful plain text recovery. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the name CVE-2008-5161 to this issue.

Note: This advisory is specific to products using RHEL5. There may be other advisories for products using other RHEL versions.

More information about these vulnerabilities can be found in the security advisory issued by RedHat Linux:

2. Avaya System Products using RHEL5 with openssh installed:

Product: Affected Version(s): Risk Level: Actions:
Avaya Voice Portal 5.0 Low Upgrade to Voice Portal 5.0 SP2 or later
Avaya Aura™ Session Manager 1.1, 5.2 Low Upgrade to Session Manager 6.0 or later

Recommended Actions:
Avaya strongly recommends that customers follow networking and security best practices by implementing firewalls, ACLs, physical security or other appropriate access restrictions. Though Avaya believes such restrictions should always be in place; risk to Avaya's product and the surrounding network from this potential vulnerability may be mitigated by ensuring these practices are implemented until such time as a product action is applied. Further restrictions as deemed necessary based on the customer's security policies may be required during this interim period.

3. Avaya Software-Only Products:

Avaya software-only products operate on general-purpose operating systems. Occasionally vulnerabilities may be discovered in the underlying operating system or applications that come with the operating system. These vulnerabilities often do not impact the software-only product directly but may threaten the integrity of the underlying platform.

In the case of this advisory Avaya software-only products are not affected by the vulnerability directly but the underlying Linux platform may be. Customers should determine on which Linux operating system the product was installed and then follow that vendor's guidance.

Product: Actions:
CVLAN Depending on the Operating System provided by customers, the affected package may be installed on the underlying Operating System supporting the CVLAN application.
Avaya Integrated Management Suite (IMS) Depending on the Operating System provided by customers, the affected package may be installed on the underlying Operating System supporting the IMS application.
Voice Portal Depending on the Operating System provided by customers, the affected package may be installed on the underlying Operating System supporting the Voice Portal application.
Avaya Aura™ Application Enablement Services 4.x Depending on the Operating System provided by customers, the affected package may be installed on the underlying Operating System supporting the AES application.

Recommended Actions:
In the event that the affected package is installed, Avaya recommends that customers follow recommended actions supplied by RedHat Linux.

4. Additional Information:

Additional information may also be available via the Avaya support website and through your Avaya account representative. Please contact your Avaya product support representative, or dial 1-800-242-2121, with any questions.

5. Disclaimer:

ALL INFORMATION IS BELIEVED TO BE CORRECT AT THE TIME OF PUBLICATION AND IS PROVIDED "AS IS". AVAYA INC., ON BEHALF ITSELF AND ITS SUBSIDIARIES AND AFFILIATES (HEREINAFTER COLLECTIVELY REFERRED TO AS "AVAYA"), DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND FURTHERMORE, AVAYA MAKES NO REPRESENTATIONS OR WARRANTIES THAT THE STEPS RECOMMENDED WILL ELIMINATE SECURITY OR VIRUS THREATS TO CUSTOMERS' SYSTEMS. IN NO EVENT SHALL AVAYA BE LIABLE FOR ANY DAMAGES WHATSOEVER ARISING OUT OF OR IN CONNECTION WITH THE INFORMATION OR RECOMMENDED ACTIONS PROVIDED HEREIN, INCLUDING DIRECT, INDIRECT, INCIDENTAL, STATUTORY, CONSEQUENTIAL DAMAGES, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF AVAYA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

THE INFORMATION PROVIDED HERE DOES NOT AFFECT THE SUPPORT AGREEMENTS IN PLACE FOR AVAYA PRODUCTS. SUPPORT FOR AVAYA PRODUCTS CONTINUES TO BE EXECUTED AS PER EXISTING AGREEMENTS WITH AVAYA.

6. Revision History:

V 1.0 - September 14, 2009 - Initial Statement issued.
V 2.0 - October 18, 2010 - Updated VP & SM actions, changed advisory status to Final.

Send information regarding any discovered security problems with Avaya products to either the contact noted in the product's documentation or securityalerts@avaya.com.

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