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Security Bulletin: Potential spoofing attack in WebSphere Application Server (CVE-2020-4421)

Security Bulletin


IBM WebSphere Application Server Liberty using openidConnectServer feature could allow spoofing identity by an authenticated user. This has been addressed.

Vulnerability Details

CVEID:   CVE-2020-4421
DESCRIPTION:   IBM WebSphere Application Liberty could allow an authenticated user using openidconnect to spoof another users identify.
CVSS Base score: 5
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L)

Affected Products and Versions

Affected Product(s) Version(s)
WebSphere Application Server Liberty


The recommended solution is to apply the interim fix or FixPack containing APAR PH24154 for each named product as soon as practical. 

For WebSphere Application Server Liberty using the openidConnectServer-1.0 feature: 
· Upgrade to minimal fix pack levels as required by interim fix and then apply Interim Fix PH24154
· Apply Liberty Fix Pack or later. 

Additional interim fixes may be available and linked off the interim fix download page.

Workarounds and Mitigations


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Change History

5 May 2020: 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 Location


[{"Business Unit":{"code":"BU053","label":"Cloud & Data Platform"},"Product":{"code":"SSEQTP","label":"WebSphere Application Server"},"Component":"Liberty","Platform":[{"code":"PF002","label":"AIX"},{"code":"PF010","label":"HP-UX"},{"code":"PF012","label":"IBM i"},{"code":"PF016","label":"Linux"},{"code":"PF033","label":"Windows"},{"code":"PF035","label":"z\/OS"},{"code":"PF017","label":"Mac OS"},{"code":"PF027","label":"Solaris"}],"Version":"Liberty","Edition":"","Line of Business":{"code":"LOB36","label":"IBM Automation"}}]

Document Information

Modified date:
08 June 2020