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Security Bulletin: IBM GSKit Certificate Chain Vulnerability in Tivoli Access Manager and IBM Security Access Manager for Web (CVE-2013-6747)

Security Bulletin


A specially constructed certificate could cause Tivoli Access Manager and IBM Security Access Manager for Web to stop responding or crash.

Vulnerability Details

CVEID: CVE-2013-6747

Tivoli Access Manager and IBM Security Access Manager for Web use digital certificates to verify the identity of client and server components. If a compromised client or server presents a specially constructed certificate, it could cause the Tivoli Access Manager or IBM Security Access Manager for Web process to use excessive resources processing the certificate. This could cause the process to become unresponsive or crash. The attack does not require local network access nor does it require authentication, but some degree of specialized knowledge and techniques are required. An exploit would not impact the confidentiality of information or the integrity of data, but the availability of the system could be compromised.

CVSS Base Score: 7.1
CVSS Temporal Score:
CVSS Environmental Score*: Undefined
CVSS Vector: (AV/N:AC/M:Au/N:C/N:I/N:A/C)

Affected Products and Versions

  • Tivoli Access Manager version 5.1 (out of service)
  • Tivoli Access Manager versions 6.0, 6.1, 6.1.1
  • IBM Security Access Manager for Web version 7.0


Customers using Tivoli Access Manager version 5.1 should upgrade to a supported version of the product.
The following versions of GSKit contain the fix for this issue:
· GSKit version or higher

How to obtain the patched GSKit versions for supported TAM versions:

1. Download the FixPack or iFix listed in the Vendor Fixes table below that matches your installed Tivoli Access Manager (TAM) and IBM Security Access Manager for Web (ISAM for Web) version.
2. Follow the instructions in the README to obtain and apply the appropriate GSKit fix for your product version.

Vendor Fix(es):

TAM/ISAM Version GSKit Version Interim Fix
TAM for e-business 6.0 GSKit v7 6.0.0-ISS-TAM-IF0032
TAM for e-business 6.1 GSKit v7 6.1.0-ISS-TAM-IF0013
TAM for e-business 6.1.1 GSKit v7 6.1.1-ISS-TAM-IF0009
ISAM for Web 7.0 GSKit v8 7.0.0-ISS-WGA-IF0004

Workarounds and Mitigations


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Complete CVSS v2 Guide
On-line Calculator v2

Related information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Change History

14 February 2014 - initial publication

*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.


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.

Document information

More support for: IBM Security Access Manager for Web

Software version: 5.1, 6.0, 6.1, 6.1.1, 7.0

Operating system(s): Platform Independent

Reference #: 1664755

Modified date: 09 January 2015