Security Bulletin: Tivoli Federated Identity Manager Business Gateway - Multiple Protocol XML signature validation bypass (CVE-2012-3314)
Tivoli Federated Identity Manager (TFIM) accepts specially crafted messages that can contain invalid or untrusted XML signatures for certain single sign-on protocols and token modules. TFIM could mistakenly accept a malicious message, allowing an attacker to perform actions as another user.
CVE ID: CVE-2012-3314
There are three related issues that can lead to this exposure. Each of these is described later in this section. All issues have the same consequence, which is that an attacker can submit a crafted message resulting in an authenticated session for a valid user account being created and the attacker having control of the session, thereby impersonating the valid user. The attack does not require that the valid user authenticate or perform any other action. The attack does not require local network access, but specialized knowledge and techniques are required. An exploit will not impact accessibility of system resources but both the confidentiality of information and the integrity of transmitted data could be compromised.
1) Incorrect error handling
SAML message components are supposed to be digitally signed, and TFIM is supposed to check the signature. However, if an attacker sent a specially crafted SAML message with certain elements unsigned, TFIM would accept the message without checking the signature.
2) Incorrect element validation
XML messages containing digital signatures elements are routinely validated by TFIM. XML digital signatures elements are generated for and valid only for specific nodes/elements in any given XML document. Consequently, any code which validates XML digital signature elements must correctly use the precise node/element that the signature was generated for. Under certain conditions, a malicious XML message with digital signature elements can be crafted which causes TFIM to use the wrong node/element for validation.
3) Incorrect certificate path validation.
XML signature validation uses certificates. These certificates can either be contained in the TFIM keystores or included within the XML signature element. When the signing certificate is included within the XML signature element, the validation process is not correctly establishing the trust relationship by validating the certificate chain of the received certificate.
CVSS Base Score: 5.8
CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:P/A:N)
All versions of Tivoli Federated Identity Manager are affected, including those no longer supported. Customers still using versions that are out of support should upgrade to a supported version to obtain the fixes for this vulnerability.
Affected supported versions:
Tivoli Federated Identity Manager versions 6.1.1, 6.2.0, 6.2.1, 6.2.2
Tivoli Federated Identity Manager Business Gateway versions 6.1.1, 6.2.0, 6.2.1, 6.2.2
Vendor Fixes: Patches and installation instructions are provided at the URLs listed below.
Complete CVSS Guide
IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog
*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.
More support for:
Tivoli Federated Identity Manager Business Gateway
Software version: 6.1, 6.2, 6.2.1, 6.2.2
Operating system(s): AIX, HP-UX, Linux, Solaris, Windows
Reference #: 1615759
Modified date: 30 October 2012