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Security Bulletin: A vulnerability in IBM® Runtime Environments Java™ Technology Edition Versions affects IBM® Db2®. (January 2021 CPU)

Security Bulletin


There are multiple vulnerabilities in IBM® Runtime Environments Java™ Technology Edition, Versions and earlier, and earlier, and earlier used by IBM® Db2®. These issues were disclosed as part of the IBM® SDKs Java™ Technology Edition updates in Jan 2021.

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

All product versions on Linux and AIX are impacted.  Windows is not impacted.

Affected Product(s)Version(s)


The recommended solution is to apply the appropriate fix for this vulnerability.

The fix for this vulnerability is in the latest version of IBM JDK. Customers running any vulnerable fixpack level of an affected Program can download the latest version of IBM JDK from Fix Central.

Affected IBM® SDKs Java™ Technology Edition, Versions :

  • and earlier
  • and earlier
  • and earlier
  • Earlier releases (6, 5.0, 1.4.2, 1.3.1, 1.2.2 etc.) may also be affected, but they are no longer supported.

Fixes for applicable vulnerabilities are included in IBM® SDKs Java™ Technology Edition, Versions :


HP is now shipping their JDK fixes twice a year, hence there is no fix available for HP-UX. The bulletin will be updated when it becomes available.

Refer to the table below to determine the IBM JDK level that contains the fix. Then follow the instructions below to perform the JDK installation.

Db2 ReleaseFixed IBM Release
v9.7.x or later
V10.1.x7.0.10.80 or later
V10.5.x7.0.10.80 or later
V11.1.x8.0.6.25 or later
V11.5.x8.0.6.25 or later

Instructions for IBM JDK Installation can be found here:

Workarounds and Mitigations


Get Notified about Future Security Bulletins




Change History

22 Apr 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.


Review the IBM security bulletin disclaimer and definitions regarding your responsibilities for assessing potential impact of security vulnerabilities to your environment.

Document Location


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Document Information

Modified date:
22 April 2021