Security Bulletin: IBM® Db2® is vulnerable to privilege escalation to root via malicious use of fenced user (CVE-2019-4057).

Summary

When a DB2 instance is created a “fenced” user is specified to run external stored procedures/user defined functions. Db2 could allow malicious user with access to the Db2 instance owner account to leverage a fenced execution process to execute arbitrary code as root. This vulnerability exists even if fenced stored procedures are not used.

Vulnerability Details

CVEID: CVE-2019-4057 DESCRIPTION: IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) could allow malicious user with access to the DB2 instance account to leverage a fenced execution process to execute arbitrary code as root.
CVSS Base Score: 6.7
CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/156567&gt; for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

All fix pack levels of IBM Db2 V9.7, V10.1, V10.5, and V11.1 editions on all platforms except Windows are affected. Windows is not 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

V10.1 | TBD | IT27204 | 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

V10.5 | FP11 | IT27192 |

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

V11.1 | FP5 | IT27203 | http://www.ibm.com/support/docview.wss?uid=ibm11115973

Workarounds and Mitigations

None.