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Security Bulletin: TLS padding vulnerability affects Communications Server for Windows (CVE-2014-8730)

Security Bulletin


Summary

Transport Layer Security (TLS) padding vulnerability via a POODLE (Padding Oracle On Downgraded Legacy Encryption) like attack affects Communications Server for Windows.

Vulnerability Details

CVE-ID: CVE-2014-8730

DESCRIPTION:

Product allows a remote attacker to obtain sensitive information, caused by the failure to check the contents of the padding bytes when using CBC cipher suites of some TLS implementations. A remote user with the ability to conduct a man-in-the-middle attack can use this vulnerability via a POODLE (Padding Oracle On Downgraded Legacy Encryption) like attack to decrypt sensitive information and calculate the plain text of secure connections.

CVSS Base Score: 4.3
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/99216 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:N/A:N)

Affected Products and Versions

Communications Server for Windows, V6.4
Communications Server for Windows, V6.1

Remediation/Fixes

Communications Server for Windows, V6.4
Upgrade Communications Server to level 6.4.0.6 and GSKit to level 8.0.50.31. Then apply the fix for JR52067. All of these are available at:
Communications Server for Windows, Version 6.4 -- Latest Fixpack

Communications Server for Windows, V6.1
Upgrade Communications Server to level 6.1.3.4 and GSKit to level 7.0.4.48. Then apply the fix for JR52061. All of these are available at:
Communications Server for Windows, Version 6.1.3 -- Latest Fixpack

Note: This might cause interoperability issues with client software if that software does not perform padding correctly.

Workarounds and Mitigations

None

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References

Complete CVSS v2 Guide
On-line Calculator v2

Related information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Change History

19 December 2014 Original Version Published

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES "AS IS" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.

Product Alias/Synonym

cswin comm server commserver csnt sna

Document information

More support for: Communications Server for Windows

Software version: 6.1.3, 6.4, 6.4.0.1, 6.4.0.2, 6.4.0.3, 6.4.0.4

Operating system(s): Windows

Reference #: 1693271

Modified date: 23 December 2014