Category Archives: Survival tips

WannaCry, Rumsfeld and Production Firewalls

21 May 2017

Today, Firewalls are the preferred means to separate a production network from a company’s intranet. Firewall configuration is performed by the Rumsfeld Conundrum: Block everything you don’t know!

Rumsfeld Conundrum for firewall configuration

Rumsfeld Conundrum for firewall configuration

For production management and IT and OT operations, we need some communication between systems in the company intranet and the production network. These required (known) connections are defined in the firewall rule base. The firewall allows communication between these known systems, and blocks any other connection attempts.

As long as the SMB V1.0 protocol is not used for communication across the firewall, the Rumsfeld Conundrum works pretty well.

Unfortunately, the SMB protocol is frequently used to implement required connections between Windows-based computers in the company intranet and the production network, e.g. for the exchange of manufacturing orders. With this, production systems become vulnerable to WannaCry although a firewall is in place because the firewall does not block communication across required connections. In the worst case, if WannaCry spreads across required connections to systems in the production network, this may result in loss of production.

Immediate action is required. The firewall rule base is a good starting point to determine how big the problem is, and to identify the systems that must be immediately patched or otherwise secured, if patching is not possible due to technical or regulatory restrictions.

Firewalls are an indispensable part of a defense in depth concept, but plain packet filtering is no effective means against attacks like WannaCry.

Have a good week, and take care of you production networks.

A key finding from the Verizon 2017 DBIR: There is no one-size-fits all strategy to IT Secutity.

7 May 2017

As always, the Verizon 2017 Data Breach Investigations Report conveys a plentiful of details about the security incidents and data breaches of the past year. A more detailed analysis of the attack patterns shows, that different industries must implement different defense in-depth strategies for effective protection against cyber-attacks.

Verizon 2017 Data Breach Investigations Report Attack Pattern Analysis

Verizon 2017 Data Breach Investigations Report Attack Pattern Analysis. Click to enlarge.

There is no one-size-fits all strategy to IT security!

Have a good week!

Some thoughts on “Zero-Day Exploits – Your Days are Numbered!”

23 April 2017

The Bromium Micro Virtualization Technology is indeed a game changer in the protection against zero-day exploits, unfortunately only for Microsoft Windows based devices.

Smart devices like smartphones, tablets or phablets are increasingly replacing the classic devices, with the consequence, that the overall security is reduced because no endpoint protection is available for those devices in general.

My worst nightmare: A tablet user downloads a word document with a zero-day exploit to an on-premise file share and opens it with Word for Windows on his laptop.

Thus, an additional endpoint protection solution, e.g. a Secure Web Gateway, is required to protect the users of smart devices, and the entire company, against internet born threats.

From my point of view, micro virtualization is great means for protection of classic computing devices against zero days. But to prevent blind spots, it must be embedded in an overall endpoint protection strategy.

Have a good weekend.

Some thoughts on „A Cyberattack on the U.S. Power Grid“ by Robert K. Knake

15 April 2017

The Contingency Planning Memorandum No. 31 „A Cyberattack on the U.S. Power Grid“, published by Robert K. Knake at the Council on Foreign Relations (CFR) in April 2017, illustrates very clearly how vulnerable critical infrastructures like the U.S. power grid are. This memorandum is really worth reading.

Ultimately, for effective protection of the society in the case of a breakdown of the power grid we need something like a nation wide operated ISMS, with hundreds of stakeholders from the private and public sector. This is a Herculean task in the U.S., and needs a miracle in Europe.

But the discussion of attack vectors is characterized by the traditional ISA 95 paradigm:

Regardless of which part of the power grid is targeted, attackers would need to conduct extensive research, gain initial access to utility business networks (likely through spearphishing), work to move through the business networks to gain access to control systems, and then identify targeted systems and develop the capability to disable them.

In the era of the IIoT, the network perimeter with all its high sophisticated security controls is no longer existent. For example, a lot of Industrial Control Systems are already connected directly to the internet today. With this, the effort for attacking critical infrastructures is decreasing, as well as the likelihood of detection.

From my point of view, it is of crucial need to take this paradigm change into account in risk management.

Happy Easter!

CVE-2017-6033 – Keep Calm and Carry on

9 April 2017

When I read the note about CVE-2017-6033 on LinkedIn and the related ICS Cert Advisory ICSA-17-094-01 on Wednesday morning my first thought was: Sounds like a really big issue if Schneider Electric recommends to upgrade to Windows 10 to solve this security issue with their Interactive Graphical SCADA System (IGSS) Software.

What happened: Someone identified a search path vulnerability in the IGSS software. This means that if an attacker manages to place e.g. a fake IGSS dynamic link library (DLL) in a path which is searched earlier than the default installation directory, then the fake DLL is executed instead of the version installed in the installation directory. Ok, this sounds really dangerous.

The CVSS V3 vector string for CVE-2017-6033 is (AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H).

The UI (User Interaction) is important in this case. UI:R (Required) means that

“Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited. For example, a successful exploit may only be possible during the installation of an application by a system administrator.”

In this case, the attacker must convince a user or administrator to copy a malicious DLL to a directory, which is searched earlier than the IGSS installation directory, to the computer where the IGSS software is installed.

To be honest, Schneider Electric’s recommendation for mitigation of this risk is somewhat oversized. End users should under no account fall into blind actionism and start migrating to Windows 10. The operational risk is far too high compared to the effort an attacker has to take to prepare the attack.

In this case, I would propose to simply make the users aware of the problem, and that’s it. If production networks are well designed and maintained and user awareness is high then there’s no need to run in the patch treadmill. To keep pace with this endless flood of patches pulls us away from doing the right and important things.

Have a good weekend.

Vastly improve your IT security in 2 easy steps?

1 April 2017

Keep your software patched and defend against social engineering, and you will win the battle against the bad guys. Let me be clear: From my point of view this is simply not enough. Nevertheless, Roger A. Grimes’ post “Vastly improve your IT security in 2 easy steps” published on March 21, 2017 at InfoWorld is really worth reading, in particular the section about patching.

The key to diminishing this risk is to identify the right software to patch and do it really, really well. The risk reducers I respect know the difference between the largest unpatched program in their environment and the unpatched program mostly likely to be exploited in their environment. A security expert knows there is usually a gulf between the two.

In particular in the production domain, where patching has always to be delayed to the next scheduled maintenance, this is a very important hint.

The big question is: How can we identify the right software on the right and important systems? Without an up-to-date asset directory with the relevant details about cyber security this is a very complex and expensive matter.

But even with an up-to-date asset directory this remains a complex task.

Rockwell/Allen Bradley Systems directly connected to the Internet

Rockwell/Allen Bradley Systems directly connected to the Internet in North America

For example, the likelihood of a cyber-attack on an Industrial Control System (ICS), which is directly connected to the internet, is many times higher than the likelihood of an attack on an ICS which is completely isolated in a security zone within the production network. The first ICS is definitely one of those systems Roger Grimes has in mind, the latter can be ignored.

But the likelihood of a cyber-attack is only half the story. For example, in functional safety the risk is the combination of the probability that a hazard will lead to an accident and the likely severity of the accident if it occurs. Thus, from this point of view, even the first ICS may be uncritical unless it is not used for controlling a critical infrastructure.

To identify the right and important systems is the hard task. It requires an up-to-date asset inventory and a smart risk management process. The plain patching process is just a piece of cake.

Have a good weekend.

Rasputin Hacker Uses SQLi to Hack 60 Universities and Government Agencies

25 March 2017

SQL injection is one of the oldest, most used and best understood attack vectors. The solution (input sanitizing) is also well understood, but still lots of systems vulnerable to SQL injection are operated on the internet. And the cybercriminal Rasputin is obviously a genius in detecting such systems.

In his post “Rasputin Hacker Uses SQLi to Hack 60 Universities and Government Agencies“, David Bisson provides some insight into the problem and why organizations are struggling with the solution:

“The evidence suggests economics play a role in causation for this troubling trend. The problem and solution are well understood, but solutions may require expensive projects to improve or replace vulnerable systems. These projects are often postponed until time and/or budget is available, until it’s too late to prevent SQLi victimization.

As always, it’s a lack of budget and resources. But especially in the case of university web sites I find this really difficult to understand.

Computer science students can work on this issues in seminars and projects after the basic database and web programming courses. Even the project management can be done by students. Only few expensive professionals are required to coordinate the activities with the universities IT department.

If one starts with the web pages where user input is requested, the major problems can be solved in short or medium term. In addition, students will get very valuable insights into real cyber security issues and how to solve them.

Have a good weekend.