Microsoft Security Bulletin MS15-040 - Important

Vulnerability in Active Directory Federation Services Could Allow Information Disclosure (3045711)

Published: April 14, 2015

Version: 1.0

Executive Summary

This security update resolves a vulnerability in Active Directory Federation Services (AD FS). The vulnerability could allow information disclosure if a user leaves their browser open after logging off from an application and an attacker reopens the application in the browser immediately after the user has logged off.

This security update is rated Important for AD FS 3.0 when installed on x64-based editions of Windows Server 2012 R2.

For more information, see the Affected Software section.

The security update addresses the vulnerability by ensuring that the logoff process properly logs off the user. For more information about the vulnerability, see the Frequently Asked Questions (FAQ) subsection for the specific vulnerability.

For more information about this document, see Microsoft Knowledge Base Article 3045711.

Affected Software

The following software versions or editions are affected. Versions or editions that are not listed are either past their support life cycle or are not affected. To determine the support life cycle for your software version or edition, see Microsoft Support Lifecycle.

Operating System

Component

Maximum Security Impact

Aggregate Severity Rating

Updates Replaced

Windows Server 2012 R2

Windows Server 2012 R2

Active Directory Federation Services 3.0
(3045711)

Information Disclosure

Important

None

Server Core installation option

Windows Server 2012 R2 (Server Core installation)

Active Directory Federation Services 3.0
(3045711)

Information Disclosure

Important

None

Note Windows Technical Preview and Windows Server Technical Preview are affected. Customers running these operating systems are encouraged to apply the update, which is available via Windows Update.

Severity Ratings and Vulnerability Identifiers

The following severity ratings assume the potential maximum impact of the vulnerability. For information regarding the likelihood, within 30 days of this security bulletin's release, of the exploitability of the vulnerability in relation to its severity rating and security impact, please see the Exploitability Index in the April bulletin summary.

Vulnerability Severity Rating and Maximum Security Impact by Affected Software

Affected Software

Active Directory Federation Services Information Disclosure Vulnerability - CVE-2015-1638

Aggregate Severity Rating

Windows Server 2012 R2

Active Directory Federation Services 3.0 when installed on Windows Server 2012 R2

Important
Information Disclosure

Important

Server Core installation option

Active Directory Federation Services 3.0 when installed on Windows Server 2012 R2 (Server Core installation)

Important
Information Disclosure

Important

Vulnerability Information

Active Directory Federation Services Information Disclosure Vulnerability - CVE-2015-1638

An information disclosure vulnerability exists when Active Directory Federation Services (AD FS) fails to properly log off a user. The vulnerability could allow unintentional information disclosure. An attacker who successfully exploited this vulnerability could gain access to a user's information by reopening an application from which the user has logged off. Since the logoff actually fails an attacker is not prompted to enter a username or password. An attacker could then use this vulnerability to discover information to which an AD FS user has access.

Servers with the AD FS role installed are affected by this vulnerability. The update addresses the vulnerability by ensuring that the logoff process properly logs off the user.

Microsoft received information about this vulnerability through coordinated vulnerability disclosure. When this security bulletin was issued, Microsoft had not received any information to indicate that this vulnerability had been publicly used to attack customers.

Mitigating Factors

Microsoft has not identified any mitigating factors for this vulnerability.

Workarounds

Microsoft has not identified any workarounds for this vulnerability.

Security Update Deployment

For Security Update Deployment information, see the Microsoft Knowledge Base article referenced here in the Executive Summary.

Acknowledgments

Microsoft recognizes the efforts of those in the security community who help us protect customers through coordinated vulnerability disclosure. See Acknowledgments for more information.

Disclaimer

The information provided in the Microsoft Knowledge Base is provided "as is" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.

Revisions

  • V1.0 (April 14, 2015): Bulletin published.

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