For the first time, let us try to speak only about defense. Thus, this article will be about different guidelines, which can help to secure your SAP system. But nothing to worry about - this post will nevertheless remain useful and interesting, even if it does not contain information about 0-days or have no words like "cyber" or "weapon" in title. So, let's go.
This blog post will be about new guideline, or standard, for securing - or testing of the security - of SAP implementations, which is going to be a first standard of the EAS-SEC standard series. There were 2 things that push us onto developing this guideline and give a second birth to our project. We thought about making some kind of guideline from the very beginning, and finally made it, when we've got a clear idea of how it should be done and what customers really needed.
And the reason we decided to make this…
… Is simple like one, two, three.
One. Questions like "why?" and "what for" are Alpha and Omega of every research. For us, as it sometimes happens, the answer came from one more additional question. After implementation of our Security Monitoring Suite for SAP in huge enterprises, making dozens of POC's and completing numerous penetration tests against SAP systems (as well as other business critical systems), the thing we were asked more often than any other was: "Guys, you are awesome! And you are doing a great job so far, finding so many problems in our installations. It's absolutely fantastic, but we don't know, where should we start to solve them. Could you provide us with top 10/20/50/100/ [put your favorite number here] most critical bugs in every area?"
Two. At the same time we had to do something completely different from just top-10 of the most critical bugs, like the one, when you can select missing SAP security notes with highest CVSS. Even if you patch all of the notes there still could remain lots of problems. For example, you may have SAP_ALL assigned to every user or you have your logs disabled so that next time, when you forget to close SAP Security Notes, to hack your system would be easy because of non-comprehensive approach. So, the challenge number one is to understand all security areas of SAP platform and to have an opportunity for every area to select a number of most critical issues. So our research first aim was to cover all SAP security areas and to be simple to implement was the second one.
Three. We started to analyze existing guidelines and standards. Currently, there are not many of them, which cover SAP security and all of them are supported by ERPScan. The guidelines we have are as follows: Secure Configuration of SAP NetWeaver® Application Server Using ABAP by SAP, ISACA Assurance (ITAF) by ISACA, and DSAG by German SAP User Group. All those standards are great, but, unfortunately, all of them have at least one big disadvantage. But let's be patient and have a better look. On those standards:
Secure Configuration of SAP NetWeaver® Application Server Using ABAP
First official SAP guide for technical security of NetWeaver ABAP in general. Before it only dozens of specific guidelines for every application were made. The first version of this guide was published in 2010, and was followed by version 1.2 in 2012. As far as it happened almost 2 years ago, we have to put in mind, that in our fast-changing world some critical things could be missing for now. This guideline was created for rapid assessment of most common technical misconfigurations in platform and consists of 9 areas and 82 checks in total.
Advantages: very brief, but quite informative (only 9 pages) and covers application platform issues, applicable for every ABAP- based platform either ERP or Solution manager or HR, it doesn't matter.
Disadvantages: 82 checks is still a lot for a first brief look on secure configuration. But what's more important, standard doesn't cover access control issues and logging and even in platform security miss some things. Finally, it gives people false sense of security if they cover all checks. But it wouldn't be completely true.
ISACA Assurance (ITAFF)
Probably, the first guideline for SAP Security. Guideline was made by ISACA consortium. There were 3 versions published in 2002, 2006 and finally - in 2009. And it means that 5 years passed from the last release and many areas are outdated now. In general, checks cover configuration and access control areas, application platform security part covers less than access control and miss some critical areas. Guideline consists of 4 parts and about 160 checks in total.
Advantages: detailed coverage of access control checks.
Disadvantages: Outdated. Technical part is missing. Guideline consists of too many checks, and can't be easily applicable by non-SAP specialist. Also it can't be applicable to any system without prior understanding of the business processes. And finally, this guideline could be found officially only as part of the book or you should be at least an ISACA member to get it.
DSAG (Deutschsprachige SAP-Anwendergruppe)
Set of recommendations from German-speaking SAP User Group. Checks cover all security areas from technical configuration and source code to access control and management procedures. Nowadays it is a biggest guideline about SAP Security. Last version was released in Jan 2013. Consists of 8 areas and 200+ checks.
Advantages: Ideal as a final step for securing SAP. Great for SAP Security administrators, covers almost all possible areas.
Disadvantages: Unfortunately, has the same problem as ISACA. It is too big for a starter, and no help at all for Security people who are not familiar with SAP. Also it can't be directly applicable to every system without prior understanding of business processes. Many checks are recommendations and user should think by himself, if they are applicable in each every case.
What goes around that comes around
So, we didn't want to make just another security guideline. But also we saw, that all of the current approaches miss something.
Finally we understood that there is a real need in new guideline. Fortunately, now we knew, what we should do to make it not good, but perfect. They all miss one general thing – they are big from one side and still doesn't cover everything but pretend to do that, which finally gives people false sense of security if they cover all checks.
The authors' efforts were to make this list as brief as possible but also to cover the most critical threats for each area. This approach is the main objective of this Guide: as despite best practices by the SAP, ISACA and DSAG, our intention was not to create just another list of issues with no explanation on why a particular issue was (not) included in the final list, but to prepare a document that may be easily used not only by SAP security experts but by every Security specialist who wants to check if his SAP is Secure and guideline should also provide comprehensive coverage of all critical areas of SAP Security.
At the same time, the development of the most complete guide would be a never-ending story as at the time of writing we had more than 7000 checks of security configuration settings for the SAP platform.
We need a guideline, which will consist of few but selected checks, and what's more important it will have future steps so that everybody will know that they made just a part of a job by implementing the standard, really critical part but not everything. So, we are talking about 80/20 rules, and we will implement it in SAP Security.
As a result, of more than 7 years experience in Security assessment of Enterprise Business applications of different types from different vendors including of cause SAP, Oracle, Microsoft, IBM but also taking into account different industry-specific systems like Retailix for Retail, MES/SCADA systems for Oil and Gas and ABS systems in Banking area our broadly experienced Pentest and Research team known for sending 450+ advisories in different products and participating in 50+ events in every continent collected information about most critical vulnerabilities and misconfigurations to understand the most critical areas. Our auditors who were responsible for different certifications like ISO, PCIDSS, PADSS, SOX and NIST in previous work analyzed those business applications from a compliance and risk point of view and finally we got 9 critical areas which are essential for security of every Enterprise Business Application and which are sorted by priority (Based on mix of Criticality, Probability, Popularity and Data needed for conducting attack).
After that we pick most critical vulnerabilities and configurations of SAP NetWeaver ABAP based applications from each of those 9 areas, and finally got 33 most critical checks.
Those are major checks that must be implemented first and can be applied to any system regardless of its type, settings and custom parameters. It is also important that these checks are equally applicable to production systems and the ones of testing and development both.
In addition to major all-purpose checks, each of 9 critical areas contains a subsection called "Further steps". This subsection gives major guidelines and instructions on what should be done in the second and third place, and then how to further securely configure each particular item. The recommended guidelines are not always mandatory and sometimes depend on a specific SAP solution.
On the one hand, with this approach, the authors were able to highlight key security parameters for a quick assessment of any SAP solution (from the ERP to the Solution Manager or Industry Solution) based on the NetWeaver ABAP platform and, on the other hand, to cover all potential problems and give complete recommendations on them.
In terms of quality, this makes the present Guide different from the SAP best practices that also contain few items, but do not cover the overall picture, as well as from best practices by ISACA and DSAG that have a lot of items, but the priorities are unclear and too complicated for the first step. Though these papers are highly valuable and absolutely necessary as next steps and they are mentioned in Further steps" areas.
And finally, you are ready to use the guideline itself (click here), made with help of overwhelming experience of ERPScan research team. Read, learn, stay secured!