Vulnerability Note VU#343971

ABB PCU400 vulnerable to buffer overflow

Overview

ABB PCU400 contains a vulnerability which can allow a remote, unauthenticated attacker to execute arbitrary code on a vulnerable system.

I. Description

The ABB PCU400 application serves as a communication gateway between RTUs that use the IEC-870-5-104 protocol and the SCADA server. The diagnostic web application contains a software flaw which allows an attacker to gain full access on the PCU400 server by sending a specially crafted packet to the X87 web interface on TCP port 8087.

Note that this issue affects PCU400 installations running the IEC60870-5-101/104 protocol based on X87.

II. Impact

A remote attacker may be able to execute arbitrary code with the privileges of the account running the x87 application.

III. Solution

Upgrade or Patch

According to ABB:

This issue is corrected in version 3.5.5 of the x87 executable. To obtain a patch or upgrade software please contact your vendor. The x87 executable is considered obsolete in newer versions of the PCU 400 and should be replaced by the newer x88 or x89 executable where applicable.

Restrict Access

This diagnostic web application is designed to be used locally. Restrictions should be put in place to limit remote access. According to ABB:

Unless there is a specific reason, a host based filter like the built-in firewall in Windows XP should be activated for the port 8087, denying access to the web interface from a remote location.

Systems Affected

Vendor	Status	Date Updated
ABB	Vulnerable		2008-10-08

References

http://www.digitalbond.com/wiki/index.php/ABB_PCU400_Remote_Buffer_Overflow
http://www.securityfocus.com/archive/1/496739/30/0/threaded

Credit

This issue was reported by Eyal Udassin and Idan Ofrat of C4 Security.

This document was written by Chris Taschner.

Other Information

Date Public	09/25/2008
Date First Published	09/25/2008 01:23:04 PM
Date Last Updated	03/03/2009
CERT Advisory
CVE Name	CVE-2008-2474
Metric	3.28
Document Revision	22

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