Security Bulletin: Privilege escalation in IBM® Db2® via loading libraries from untrusted path (CVE-2018-1487).

Summary

Db2 loads shared libraries from an untrusted path potentially giving low privilege user full access to the DB2 instance account by loading a malicious shared library. All instance owner executables that run with elevated privileges (setuid) are affected. Root setuid executables are not affected.

The implication is that if the customer has implemented their own applications which run with elevated privileges (setuid) those are affected as well, and it is up to the customer to ensure that the DB2INSTANCE environment variable is correctly set to the Db2 instance owner, and not modified by a malicious user.

Vulnerability Details

CVEID: CVE-2018-1487 DESCRIPTION: IBM DB2 for Linux, UNIX and Windows (includes DB2 Connect Server) binaries load shared libraries from an untrusted path potentially giving low privilege user full access to the DB2 instance account by loading a malicious shared library.
CVSS Base Score: 8.4
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/140972 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/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.

Remediation/Fixes

The recommended solution is to apply the appropriate fix for this vulnerability and, in the case that the customer is implementing their own setuid applications, to ensure the DB2INSTANCE environment variable is correct and not modified by a malicious user.

FIX:

The fix for DB2 release V10.5 is in V10.5 FP10 and V11.1 is in V11.1.3.3 iFix002, which are available for download from Fix Central.

Customers running any vulnerable fixpack level of an affected Program, V9.7 and V10.1 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 and V10.1 FP6. They can be applied to any affected fixpack level of the appropriate release to remediate this vulnerability.

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 | IT24476 | 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 | FP10 | IT24475 | <https://www-01.ibm.com/support/docview.wss?uid=swg24045012&gt;
V11.1.3.3 | iFix002 | IT24474 | <https://www-01.ibm.com/support/docview.wss?uid=ibm10720009&gt;

Workarounds and Mitigations

None.