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

Security Bulletin


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.

Workarounds and Mitigations

None.

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Reference

Complete CVSS v3 Guide
On-line Calculator v3

Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Acknowledgement

The vulnerability was reported to IBM by Rich Mirch.

Change History

July 6, 2018: Original Version Published.
July 11, 2018: Updated 10.5 version with a link to 10.5 FP10 image.
August 7, 2018: Updated 11.1 version with a link to 11.1.3.3 iFix002 image.

*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.

Disclaimer

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 information

More support for: DB2 for Linux, UNIX and Windows

Component: --

Software version: 9.7, 10.1, 10.5, 11.1

Operating system(s): AIX, HP-UX, Linux, Solaris

Software edition: Advanced Enterprise Server, Advanced Workgroup Server, Enterprise Server, Express, Express-C, Personal, Workgroup Server

Reference #: 2016505

Modified date: 07 August 2018