Security Bulletin: IBM System x and Flex Systems Browser Exploit Against SSL/TLS (BEAST) Mitigations (CVE-2011-3389)

Summary

Security Bulletin: IBM System x and Flex Systems Browser Exploit Against SSL/TLS (BEAST) Mitigations (CVE-2011-3389)

Vulnerability Details

Summary

The SSL 3.0 and TLS 1.0 protocols when used with Cipher Block Chaining (CBC) mode with chained initialization vectors may allow man-in-the-middle attackers to obtain plaintext HTTP headers.

Content

Vulnterability Details

CVE ID: CVE-2011-3389

Description:

The SSL protocol, as used in certain configurations in Microsoft Windows and Microsoft Internet Explorer, Mozilla Firefox, Google Chrome, Opera, and other products, encrypts data by using CBC mode with chained initialization vectors, which allows man-in-the-middle attackers to obtain plaintext HTTP headers via a blockwise chosen-boundary attack (BCBA) on an HTTPS session, in conjunction with JavaScript code that uses (1) the HTML5 WebSocket API, (2) the Java URLConnection API, or (3) the Silverlight WebClient API, aka a “BEAST” attack. (From the National Vulnerability Database)

CVSS:
CVSS Base Score: 4.3
CVSS Temporal Score: See <http://xforce.iss.net/xforce/xfdb/70069&gt; 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

List the affected versions/releases/platforms, as best possible.

• Flex System Chassis Management Module, Option part number 68Y7029
• Flex System Enterprise Chassis, type 7893, any model
• Flex System Enterprise Chassis, type 8721, any model
• Flex System Enterprise Chassis, type 8724, any model
• Flex System x220 Compute Node, Types 7906, 2585, any model
• Flex System x240 Compute Node, Types 8737, 8738, 7863, any model
• Flex System x440 Compute Node, Type 7917, any model
• Flex System Manager Node, Types 7955, 8731, 8734, any model
• Flex System V7000 Dual Controller Storage Node, Type 4939, any model
• System x3100 M4, Type 2582, any model
• System x3250 M4,Type 2583, any model
• System x3300 M4, Type 7382, any model
• System x3500 M4, Type 7383, any model
• System x3530 M4, Type 7160, any model
• System x3550 M4, Type 7914, any model
• System x3630 M4, Type 7158, any model
• System x3630 M4 HD, Type 5466, any model
• System x3650 M4, Type 7915, any model
• System x3650 M4 HD, Type 5460, any model
• System x3750 M4, Types 8722, 8733, 8752, any model
• iDataPlex dx360 M4, Types 7912, 7913, any model
• IBM System x iDataPlex Direct Water Cooled dx360 M4 server, Types 7918, 7919, any model
• BladeCenter HS23, Types 7875, 1929, any model
• BladeCenter HS23E, Types 8038, 8039, any model
• IBM BladeCenter S
• IBM BladeCenter H
• IBM BladeCenter E
• IBM BladeCenter HT
• IBM Advanced Management module

Remediation:

Browsers contain a mitigation for this issue, as described below under “Mitigation(s).” The following firmware versions also support TLS 1.2, which is not vulnerable to this issue. Firmware updates are available through IBM Fix Central.

1.3.1 or newer

IBM BladeCenter Advanced Management Module (AMM) | v3.66B or newer

Many ports on the Integrated Management Module v2, Chassis Management Module, and Flex System Manager can be restricted to use only the TLS 1.2 version of the SSL/TLS protocol. For additional information please see the following document: http://pic.dhe.ibm.com/infocenter/flexsys/information/index.jsp?topic=%2Fcom.ibm.acc.8731.doc%2Fusing_tls12.html Please note that when using the firmware versions listed above configuring the Chassis Management Module automatically configures any Integrated Management Module v2 and Power Service Processor in the chassis. The instructions given for configuring the IMM2 are only required for IMM2 outside the IBM Flex Systems chassis.

Workaround

None

Mitigation

Mozilla Firefox, Internet Explorer, Google Chrome, and Opera contain a browser-side mitigation for this issue. It is known as the 1/n-1 splitting mitigation. Communication between browsers and servers is protected as long as the system with the browser has an up-to-date version of Java and up to date version of Mozilla Firefox, Internet Explorer, Google Chrome, or Opera. If using Internet Explorer, it’s also important to have the appropriate Windows patch, as described here: <http://technet.microsoft.com/en-us/security/bulletin/ms12-006&gt; In other words, if all users who access the system have up to date software, the connection to the system is not vulnerable to this attack. Consult Java and browser documentation for specific information regarding which patches should be applied or which version should be used.

References:

• Complete CVSS Guide
• On-line Calculator V2
• <http://xforce.iss.net/xforce/xfdb/70069&gt;

Related Information:

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Acknowledgement

None

Change History

10 September 2013: Original copy published
06 December 2013:Â Added information regarding additional affected products
10 January 2014: Added information regarding additional affected products and the feature to restrict to TLS 1.2.

*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 Flash.

Note: 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.