[VulnWatch] Internet Communication Manager Denial Of Service Attack

From: NGSSoftware Insight Security Research (mark@private)
Date: Thu Jul 05 2007 - 08:52:05 PDT

Name: Internet Communication Manager Denial Of Service Attack
Release Date:  5 July 2007
Reference: NGS00484
Discover: Mark Litchfield <mark@private>
Vendor: SAP
Vendor Reference: SECRES-287
Systems Affected: Confirmed on Windows (unconfirmed on *NIX)
Risk: High
Status: Fixed

Discovered:  3 January 2007
Released: 19 January 2007
Approved: 29 January 2007
Reported: 11 January 2007
Fixed:  2 May 2007

Internet Communication Manager ensures communication between the SAP Web
Application Server with the WWW using the HTTP, HTTPS and SMTP protocols.
ICM is part of the SAP Web Application Server and is implemented as an
independent process (ICMAN.exe) and is started and monitored by the

The Internet Communication Manager also offers the ICM Server Cache as
part of its functionality, using the ICM server cache increases
performance considerably.  The ICM server cache (also known as the
Internet Server Cache saves HTTP(S) objects before they are sent back to
the requesting client.  The next time an object is requested, the
application gets the contents directly from the cache before sending it to
the client.

However, it is possible to configure the Web dispatcher to act as a web
cache.  For more information visit -

A method by which to determine if the Internet Communication Manager is
acting as the web cache, we can make the following request:


An error will be returned:

500 Internal Server Error


Error: -15
Version: 7010
Component: HTTP_CACHE
Date/Time: xxxxxxxxxxxxxxxx
Module: http_cache.c
Line: 2640
Server: Target_JP1_01
Error Tag: {-}
Detail: Object not found (key='ngs')

Technical Details
By passing a URI of 264 bytes the ICMAN.exe process terminates.  This
includes the length of the requested file, the file extension, the ?, the
paramter 'sap-isc-key=' and the value.

This is an very effective Denial of Service attack within a SAP

Fix Information
Please ensure you have the latest version

NGSSoftware Insight Security Research
+44(0)208 401 0070 

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