Security Bulletin: IBM® Db2® does not explicitly forbid a weaker than expected 3DES cipher when configured to use SSL (CVE-2019-4102).

Summary

TLS 1.2 allows the use of 3DES, which has some known weaknesses, among other supported ciphers. Db2 does not forbid the use of 3DES when configured to use TLS 1.2 protocol. Although Db2 does not choose the cipher out of all available ciphers, the weaker ciphers should be explicitly forbidden for use. Customers who provide SSL_CIPHERSPECS with both 3DES and non-3DES ciphers specified are vulnerable. This update will never use the 3DES cipher even if specified in the SSL_CIPHERSPECS list.

Vulnerability Details

CVEID: CVE-2019-4102 DESCRIPTION: IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) uses weaker than expected cryptographic algorithms that could allow an attacker to decrypt highly sensitive information.
CVSS Base Score: 5.9
CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/158092&gt; for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

Affected Products and Versions

All fix pack levels of IBM Db2 V9.7, V10.1, V10.5, and V11.1 editions on all platforms are affected.

Remediation/Fixes

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

FIX:

The fix for Db2 V11.1 is in V11.1.4.5, available for download from Fix Central.
The fix for Db2 V10.5 is in V10.5.0.11, available for download from Fix Central.

Customers running any vulnerable fixpack level of an affected Program, V9.7, V10.1, and V10.5, can download the special build containing the interim fix for this issue from Fix Central. These special builds are available based on the most recent fixpack level for each impacted release: DB2 V9.7 FP11, V10.1 FP6, and V10.5 FP10. They can be applied to any affected fixpack level of the appropriate release to remediate this vulnerability.

Images published before July 24, 2019 have an issue with db2iupdt. Customers that have downloaded a special build before July 24, 2019 should delete the image and re-download with the updated links below. Alternatively, see this technote for instructions on how to manually resolve the issue with older images: <http://www.ibm.com/support/docview.wss?uid=ibm10959065&gt;

AIX 64-bit
HP-UX 64-bit
Linux 32-bit, x86-32
Linux 64-bit, x86-64
Linux 64-bit, POWER™ big endian
Linux 64-bit, System z®, System z9® or zSeries®
Solaris 64-bit, SPARC
Solaris 64-bit, x86-64
Windows 32-bit, x86
Windows 64-bit, x86

V10.1 | TBD | IT28269 | Special Build for V10.1 FP6:

AIX 64-bit
HP-UX 64-bit
Linux 32-bit, x86-32
Linux 64-bit, x86-64
Linux 64-bit, POWER™ big endian
Linux 64-bit, System z®, System z9® or zSeries®
Solaris 64-bit, SPARC
Solaris 64-bit, x86-64
Windows 32-bit, x86
Windows 64-bit, x86

V10.5 | FP11 | IT28252 |

<https://www.ibm.com/support/pages/node/3500079&gt;

V11.1 | FP5 | IT28267 | http://www.ibm.com/support/docview.wss?uid=ibm11115973

Workarounds and Mitigations

Remove 3DES from the SSL_CIPHERSPECS list.