SAP Dissector Plugin for Wireshark

Copyright (C) 2012-2017 by Martin Gallo, Core Security

Version 0.5.1 (October 2017)

Overview

SAP Netweaver [1] is a technology platform for building and integrating SAP business applications. Communication between components uses different network protocols. While some of them are standard and well-known protocols, others are proprietaries and public information is not available.

This Wireshark [2] plugin provides dissection of SAP's NI, Message Server, Router, Diag, Enqueue and SNC protocols. The dissectors are based on information acquired at researching the different protocols and services. Additional experimental support is included for SAP's RFC protocol. Detailed information about the research can be found at [3], [4], [5], [6] and [7].

Features

This plugin counts on several different dissectors:

• SAP NI Protocol dissector

  This is the dissector for SAP's Network Interface (NI) protocol. The dissector handles the reassemble of fragmented TCP packets and identifies keep-alive messages (PING/PONG). It also calls the respective sub-dissector according to the port being used.

• SAP Router Protocol dissector

  This dissector includes support for the SAP Router protocol, handling route, control messages and error information packets. The dissector also calls the SNC sub-dissector when SNC frames are found.

• SAP Diag Protocol dissector

  The main dissector of the plugin. It dissects the main headers used by the Diag protocol: DP, Diag and Compression headers. The dissector also handles decompression of the payload data and includes dissection of relevant Diag payload items, including Support Bits and common APPL/APPL4 items. Wireshark's expert information capabilities are used to remark malformed or wrong packets. The dissector also calls the RFC sub-dissector when an embedded RFC call is found and the SNC sub-dissector when SNC frames are found.

• SAP Message Server Protocol dissector

  This module dissects the packets used by SAP's Message Server Protocol in its binary non-HTTP format, for both internal and external ports.

• SAP Enqueue Protocol dissector

  This module dissects packets used by SAP's Standalone Enqueue and Replication Servers.

• SAP SNC (Secure Network Connection) Protocol dissector

  This dissector parses SNC frames and their fields. When the frames contains wrapped data that wasn't encrypted, it allows calling dissectors to get access to the unwrapped data for further dissecting it, as the case of Diag dissector when SNC is used in authentication only or integrity protection quality of protection levels.

• SAP RFC (Remote Function Call) Protocol dissector (experimental)

  This dissector perform some basic dissection on the main components of the RFC protocol. It dissects general items and does some basic reassembling and decompression of table contents.

Installation & Build

This Wireshark plugin is not distributed as part of the Wireshark source. It can be build as a standalone plugin, or as part of Wireshark, and is compatible with version 2.4.

Installing on Linux

As a standalone plugin

To build and install the plugin on Debian/Ubuntu linux distributions:

sudo add-apt-repository ppa:wireshark-dev/stable -y
sudo apt-get update
sudo apt-get install wireshark wireshark-dev
git clone https://github.com/CoreSecurity/SAP-Dissection-plug-in-for-Wireshark/
cd SAP-Dissection-plug-in-for-Wireshark/
mkdir build
cd build
cmake ..
make
make install

As part of Wireshark

The following steps are required to build and install the plugin as part of Wireshark:

1. Download and decompress the Wireshark version 2.4 source [8] or checkout the code from the source repository [9].

   git clone https://code.wireshark.org/review/wireshark cd wireshark git checkout master-2.4

2. Copy the SAP Wireshark Plugin to a new plugins/sap directory.

   git clone https://github.com/CoreSecurity/SAP-Dissection-plug-in-for-Wireshark/ plugins/sap

3. Configure the plugin to be included in the build process. This step can be performed using the patch file provided. At the root directory run:

   git apply plugins/sap/wireshark-master-2.4.patch

4. Perform a new build including the plugin. At the root directory run:

   mkdir -p build cd build cmake .. make make install

Using Vagrant

Vagrant is a Virtual Machine management software that allows creating reproducible virtual machines. In order to make it easier to compile and test the plugin, a pre-configured Vagrantfile is provided for using it with Vagrant 1.8. The Vagrantfile provided with the plugin is configured to use VirtualBox and perform a build of the plugin inside a Ubuntu 16.04 distribution.

Two machines are provided to build the plugin:

• source: for building the plugin as part of Wireshark.
• standalone: for building the plugin as a standalone plugin.

The following steps can be used to setup a Vagrant machine and build the plugin:

1. Install VirtualBox and Vagrant 1.8 or greater.

   sudo apt-get install virtualbox vagrant

2. Inside the plugin's directory, launch the desired Vagrant machine, in this case standalone:

   vagrant up standalone

3. Login into the Vagrant machine and run Wireshark:

   vagrant ssh standalone wireshark

Installing on Windows

Windows build can be only performed as part of the whole Wireshark. The following steps are required to compile the plugin on Windows:

1. Follow the step-to-step guide [10] for building Wireshark on Windows.

2. Copy the SAP Wireshark Plugin to a new plugins/sap directory.

3. Configure the plugin to be included in the build process. This step can be performed using the patch file provided. At the root directory run:

   git apply plugins/sap/wireshark-master-2.4.patch

4. Perform a new build including the plugin.

Installing on OSX

The build process for OSX is similar to the one for Linux systems. It was reported that compiling Wireshark on OSX requires fixing link for the gettext library if it was installed using home-brew.

Penetration testing distribution and frameworks

The plugin is available for installation on several penetration testing distributions and frameworks.

Installing on Pentoo

Installation on the Pentoo livecd distribution:

emerge net-misc/wireshark-sap-plugin

Installing with The PenTesters Framework (PTF)

Installation on Debian, Ubuntu and ArchLinux can be performed using The PenTesters Framework (PTF). From inside the ptf command-line, run:

use modules/intelligence-gathering/sap-wireshark-plugin install

Additional notes

It's worth mentioning that compression libraries for SAP Diag/RFC protocol are originally written in C++, thus the entire plugin needs to be compiled for C++. See Wireshark's portability notes for more information [11].

Usage

Traffic dissection

After the plugin is installed, it will automatically dissect SAP protocols' traffic if using default ports. If required, ports can be modified on SAP NI protocol as well as sub-dissectors' preferences.

SAP Diag Gui Logon Password filter

DYNT_ATOM items contains data entered into screen fields. The following filter could be used for identifying packets containing fields marked as "invisible" (fields that are masked in the SAP GUI screen) in search for sensitive data. Early packets in a Diag session probably contains values for user id and password fields.

sapdiag.item.value.dyntatom.item.attr.INVISIBLE == 1

The same results can be achieved also using expert info (security group):

sapdiag.item.value.dyntatom.item.password

License

This Wireshark plugin is distributed under the GPLv2 license. Check the COPYING file for more details.

Authors

The library was designed and developed by Martin Gallo from the Security Consulting Services team of Core Security.

Contributors

Contributions made by:

• Joris van de Vis (@jvis)
• Anton Bolshakov (@blshkv)
• Valeriy Gusev
• Daniel Berlin (@daberlin)
• Victor Portal Gonzalez
• Dave Hartley (@nmonkee)
• Jean-Paul Roliers
• Dongha Shin
• Luca Di Stefano
• Alexis La Goutte (@alagoutte)

References

[1] https://www.sap.com/platform/netweaver/index.epx

[2] https://www.wireshark.org/

[3] https://www.coresecurity.com/corelabs-research/open-source-tools/sap-dissection-plug-in-wireshark

[4] https://www.coresecurity.com/content/sap-netweaver-dispatcher-multiple-vulnerabilities

[5] https://www.coresecurity.com/content/SAP-netweaver-msg-srv-multiple-vulnerabilities

[6] https://www.coresecurity.com/corelabs-research/publications/uncovering-sap-vulnerabilities-reversing-and-breaking-diag-protocol-brucon2012

[7] https://www.coresecurity.com/corelabs-research/publications/sap-network-protocols-revisited

[8] https://www.wireshark.org/download.html

[9] https://code.wireshark.org/review/wireshark

[10] https://code.wireshark.org/review/gitweb?p=wireshark.git;a=blob_plain;f=doc/README.developer;hb=refs/heads/master-2.4

[11] https://www.wireshark.org/docs/wsdg_html_chunked/ChSetupWin32.html

Contact

Whether you want to report a bug or give some suggestions on this package, drop us a few lines at [email protected] or contact the author email [email protected].