Security Bulletin: For safer IBM Notes single sign on with Windows, use Notes Shared Login or Notes Federated Login (CVE-2013-0522)
Notes Client Single Logon uses an operating system communication mechanism for password transmission between Windows and Notes that can be attacked by malicious code planted on the user workstation to reveal the user password. To prevent the potential for attack, disable Notes Client Single Logon and instead opt to use the more secure Notes Shared Login or Notes Federated Login.
CVE ID: CVE-2013-0522
When adopting any single sign on solution, administrators face the tough trade-off between usability (a single password granting access to multiple systems) and better security (different passwords for different systems). A single password for multiple systems is obviously popular with users, while different passwords for different systems is popular with security-minded administrators. However, when these administrators prevail, users often resort to writing down multiple passwords. And so grows the demand for better single sign on solutions.
Notes Client Single Logon uses an operating system communication mechanism for password transmission between Windows and Notes that can be attacked by malicious code planted on the user workstation to reveal the password of an authenticated user. To prevent the potential for attack, disable Notes Client Single Logon and instead opt to use the more secure Notes Shared Login or Notes Federated Login.
For more information on Notes Shared Login, see
For more information on Notes Federated Login, see section "Using Security Assertion Markup Language (SAML) to configure federated-identity authentication" in
For more information on disabling Notes Client Single Logon, refer to the Note in the following Help topic:
For a comparison of Notes Client Single Logon and Notes Shared Login, see technote 1437726.
Using the Common Vulnerability Scoring System (CVSS) v2, the security rating for this issue is:
CVSS Base Score: 4.1
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/82531 for the current score.
CVSS Environmental Score: Undefined
CVSS String: (AV:L/AC:M/Au:S/C:P/I:P/A:P)
Access Vector: Local Access Complexity: Medium
Authentication: Single Confidentiality Impact: Partial
Integrity Impact: Partial Availability Impact: Partial
Any version of IBM Notes running on Windows with Notes Client Single Logon enabled.
To prevent the potential for attack, disable Notes Client Single Logon and instead opt to use the more secure Notes Shared Login or Notes Federated Login.
1. For your Notes Execution Control list settings for -Default- and -No Signature-, do NOT allow access to File system, External code or External programs.
2. Frequently change your Windows password with length and complexity commensurate to the information it protects.
3. Use Windows screen saver password to prevent unauthorized access to your workstation.
Complete CVSS Guide
On-line Calculator V2
X-Force Vulnerability Database: https://exchange.xforce.ibmcloud.com/vulnerabilities/82531
IBM Product Security Incident Response Program
This vulnerability was reported to IBM by Markus Piéton of it.sec GmbH & Co. KG.
|24 April 2013||Initial publish|
*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.
|Messaging Applications||Lotus End of Support Products||Lotus Notes||7.0, 6.5|
More support for:
Software version: 8.0, 8.0.1, 8.0.2, 8.5, 8.5.1, 8.5.2, 8.5.3, 9.0
Operating system(s): Windows
Reference #: 1634508
Modified date: 24 April 2013