Arbitrary Library Loading in Informix

NGSSoftware Insight Security Research Advisory

Name: Arbitrary Library Loading in Informix
Systems Affected: All versions of Informix
Severity: High
Vendor URL: http://www.ibm.com/
Author: David Litchfield [ [email protected] ]
Date of Public Advisory: 2nd August 2006
Advisory number: #NISR02082006C
CVEID: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-3855
Advisory URL: http://www.ngssoftware.com/research/

Description

Informix Dynamic Server is a database developed by IBM. An attacker can
force to the database server to load an arbitrary library and thus execute
arbitrary code.

Details

The ifx_load_internal SQL function can be used to load an arbitrary library
into the address space of the database server process. By placing code in
the DllMain() function on Windows or _init() on Linux an attacker can have
this code execute automatically when the library is loaded. In conjunction
with exploiting other flaws it is possible to remotely create a library over
SQL, dump this to the server disk and then load it.

Fix Information

IBM was alerted to this flaw on the 18th January 2005. Revoking execute
permission on ifx_load_internal SQL function from public will remove the
risk of exploitation of this issue.

NGSSQuirreL for Informix, an advanced vulnerability assessment scanner
designed specifically for Informix, can be used to accurately determine
whether your servers are vulnerable to this flaw. More information about
NGSSQuirreL for Informix can be found here
http://www.ngssoftware.com/products/database-security/ngs-squirrel-informix.php

About NGSSoftware

NGSSoftware develops vulnerability assessment and compliancy tools for
database servers including Oracle, Microsoft SQL Server, DB2, Sybase and
Informix. Headquartered in the United Kingdom NGS has offices in London, St.
Andrews (UK), Sydney, Brisbane, and Perth (Australia) and Texas in the
United States; NGSConsulting provide services to some of the largest and
most demanding organizations around the globe.

http://www.ngssoftware.com/

Telephone +44 208 401 0070
Fax +44 208 401 0076

[email protected]