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Security Bulletin: A vulnerability in IBM Java affects IBM ILOG CPLEX Optimization Studio (CVE-2020-27221)

Security Bulletin


There is a vulnerability in IBM® Java™ versions 7 & 8 used by IBM CPLEX Optimization Studio. IBM CPLEX Optimization Studio has addressed the applicable CVE.

Vulnerability Details

CVEID:   CVE-2020-27221
DESCRIPTION:   Eclipse OpenJ9 is vulnerable to a stack-based buffer overflow when the virtual machine or JNI natives are converting from UTF-8 characters to platform encoding. By sending an overly long string, a remote attacker could overflow a buffer and execute arbitrary code on the system or cause the application to crash.
CVSS Base score: 9.8
CVSS Temporal Score: See: for the current score.
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

Affected Product(s)Version(s)
IBM ILOG CPLEX Optimization Studio (COS)20.1
IBM ILOG CPLEX Optimization Studio (COS)12.10
IBM ILOG CPLEX Optimization Studio (COS)12.9
IBM ILOG CPLEX Optimization Studio (COS)12.8
IBM ILOG CPLEX Optimization Studio (COS)12.7.1
IBM ILOG CPLEX Optimization Studio (COS)12.7


The recommended solution is to download and install the appropriate version of IBM JRE as soon as practicable.
Before installing a newer version of IBM JRE, please ensure that you:

  • Close any open programs that you may have running;
  • Rename the initial directory of the IBM JRE (for example: with a .old at the end),
  • Download and install the appropriate IBM JRE version.

IBM ILOG CPLEX Optimization Studio

You must verify that applying this fix does not cause any compatibility issues.
Here are the detailed instructions for updating IBM JRE.

For Mac OS, HP-UX and Solaris, IBM recommends upgrading to a fixed, supported version/release/platform of the product.

Workarounds and Mitigations


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Change History

16 Mar 2021: 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":"BU025","label":"IBM Cloud and Cognitive Software"},"Product":{"code":"SSSA5P","label":"IBM ILOG CPLEX Optimization Studio"},"Component":"","Platform":[{"code":"PF033","label":"Windows"},{"code":"PF002","label":"AIX"},{"code":"PF016","label":"Linux"},{"code":"PF051","label":"Linux on IBM Z Systems"},{"code":"PF017","label":"Mac OS"}],"Version":"12.7,12.7.1,12.8,12.9,12.10","Edition":""}]

Document Information

Modified date:
16 March 2021