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Buffer Overflow, a Common Attack

Data can exceed a buffer’s capacity. Not many people may know or have heard about buffer overflow, but we are here to help you understand this dangerous web threat. To put it simply, most programs that run in our computers manipulate data of some form. This data could originate from data associated with the program or logged data that is stored on your computer. The computer assigns this data to a temporary storage, also known as a “buffer”, where they can be quickly used and deployed.

buffer overflow

What is Buffer Overflow?

Now, imagine a buffer as an empty cup that can be filled with water or ice. It has the capacity to store a fixed amount of water or, in this case, data. If there is more water than it can hold, the water will leak and overflow onto your table. Buffer overflow happens in a very similar, albeit a bit more complicated way. Buffers have a limited amount of data they can store and if the buffer is overwhelmed with extra data, it will naturally fall into adjacent buffers to make up the storage.

The overflow of data can be caused by a simple programming error made during its development. However, malicious hackers are able to enact an overflow and perform severe damage to any computing system.

How Does Buffer Overflow Affect You?

According to the SANS Institute, a buffer overflow may cause havoc on network systems and applications. More specifically, buffer overflows can:

  1. Corrupt data that was stored in other buffers, which may lead to a 404 error.
  2. Interrupt the normal flow of programs.
  3. Shut down an operating system.
  4. Run malicious programs through the excess data.

So How Can I Prevent Buffer Overflow?

Buffer Overflow comes in many sizes and these days, they can come also as viruses. Therefore, if you don’t have a firewall and an antivirus software, we strongly advise to install them at once. Make updates as soon as possible when your antivirus and firewall programs ask your permission. In addition, avoid opening unknown and suspicious emails as they can execute malicious programs or malware that can lead to your PC becoming a zombie bot. Don’t install suspicious third party programs because this could be a gateway to allow hackers to mess with your operation system.


This blog post was originally featured on cloudbric.com. Visit their blog for more insight, news, and accessible information on web threats and trends. If you would like to learn more about Cloudbric’s logic-based WAF service, please contact info@cloudbric.com.

cafe using public wifi on a laptop

Public Wi-Fi: Stranger Danger

Progress in the IT world have led to a good amount of changes in the past decade. Nowadays, we’re surrounded by technology and it’s a part of our everyday lives. One of these technologies that we don’t even give much thought to anymore is public Wi-Fi.

It certainly has made life a lot easier. We don’t have to consistently rely on the quickly-disappearing amounts of cellular data we have on our mobile phones. Especially in Korea, one of the most connected countries in the world in terms of network infrastructure and #1 in terms of internet speed, free public Wi-Fi is thought of as a given. It’s a win-win situation: Businesses will get more foot traffic from tourists or residents who are seeking a location with a Wi-Fi connection and entertainment, and customers will be connected to the Internet for free without the need to use their precious cellular data.

But the issue here is this: is public Wi-Fi really safe?

Cafes are often a popular place for students and freelancers alike because they provide nice ambiance, open spaces, and most of the time – free Wi-Fi. Many cafes have their Wi-Fi passwords on display at the counter, or written on the receipt. Most of the time it’s something easy like “1234567.” However, when a simple string of characters is on display, it’s no longer fulfilling its original duty of acting as a “secret code” to access a device.

And the fact is that there has been an increase in the hacking of public wireless routers as of late. The most prevalent of these hacking methods is called “wireless sniffing.” Just as the name suggests, wireless sniffers are specifically created to “sniff out” data on wireless networks. A sniffer is a piece of software or hardware that intercepts data when it’s transmitted. This decodes data so that it’s readable for humans.  If a wireless sniffer accesses your connection, your ID or password may be found, or your device could be infected with malware.

Awareness of Public Wi-Fi Security Issues

This is all anxiety-causing information, but we started to wonder two things in terms of application to the real-world. First, how is the security at some of the well-known establishments providing Wi-Fi ? And second, were providers (at cafes, bookstores, etc.) and users aware of security (or the lack thereof) for public Wi-Fi?  

public wifi infographic regarding cafesin seoul

The Public Wi-Fi “Provider”

After surveying 20-odd establishments, we categorized them into three levels of security. In terms of “high” level, authorization and authentication was required in order to gain access. For “average,” a different password was set from the original factory settings, and for “low” – no changes had been made to the router since the point of purchase. Not surprisingly, we found that the larger chains offered higher measures of security than the domestic brands. Independent cafes rarely had the level of security necessary to secure a Wi-Fi connection.public wi-fi awareness by providers of routers

We then conducted a short interview with either the employee behind the counter or the branch manager and found that many locations don’t regularly upgrade their firmware. Upgrading your firmware regularly makes sure that your router is stable and optimized to take on the traffic. Although it can be a tedious process, it’s a necessity. And while some locations changed their password after buying the router, it was often a simple password. Additionally, none of the establishments had been changing their passwords regularly.

Most cafes will have a simple password (or no password at all) because it’s more convenient. However, a few simple steps can set you on the right track to begin protecting your establishment. After all, a business needs to look at customer loyalty and long-term growth. That isn’t going to happen if you or your customers are hacked.

 4 easy steps to secure the public Wi-Fi of your establishment:

  1. Change the ID and password from the default factory settings regularly.
  2. Secure your Wi-Fi by changing settings to WPA (Wi-Fi Protected Access), rather than WEP (Wireless Encryption Protocol). WEP has issues of static encryption keys, making it easier to access..
  3. Block remote access
  4. Update firmware regularly

The Public Wi-Fi “User”

We went on to interview customers who were utilizing the public Wi-Fi at the cafes to get their views on security. However, we were surprised by the users because the knowledge of security issues was better than that of the providers. Although Wi-Fi users are sometimes aware that it may be unsafe, because it’s free and convenient, they ignore the risks and access the network anyway.

So what are the basic steps you can take that won’t take too much of your time/money?

public wi-fi awareness by users

4 Cautionary Steps for Using Public Wi-Fi

  1. Turn off sharing on your computer – make sure that remote login is not possible.
  2. Consider using a VPN (Virtual Private Network) when connecting to public Wi-Fi. Because it will encrypt your data, it can help prevent criminals from sniffing.
  3. Avoid sites that take your ID and password (i.e. banking, online shopping).
  4. Go to a cafe or public Wi-Fi hotspot where you know the security measures the provider takes.

But in all honesty, public Wi-Fi will never be “safe” in the sense that it will be void of any security risks.

And if you must…

It’s not realistic to say that all public Wi-Fi must disappear. In the digitized 21st century, connectivity is inevitable. In fact, it’s already happening. So the best thing you can do as a user and provider is to be cautious. Have these steps ready to execute. Extra steps are also possible with a firewall, anti-malware products, etc. But remember, the first step is the most important.

car security using gps or navigation

The Smart Car Trend (Part 2): Car Security?

In part 1 of the series, we talked about how smart cars are trending, and how companies are scrambling to get in on the action. But today, let’s talk about the often conveniently-omitted issue of car security. As automobiles are using the network and cloud more and more to provide online services, there’s a growing concern for the field smart car security.

When “smart car security” is mentioned, many will first think of the Jeep Cherokee that was hacked last year. Even before the terminology of “connected and smart cars” was widespread, “telematics” was used by vehicles. Telematics is the branch of IT dealing with long-distance transmission of computerized information. In the case of the Jeep Cherokee, the telematics was hacked in order to take control of the car.

Our electronic devices like smartphones or PCs have a standardized set of protocols and a key management system so that they can safely secure their systems. But this is a stark contrast from automobile companies, who each have their own “secret protocol” for their services. However, most lack a firewall or a way to detect trespassers in their systems. Companies may claim that they’ve analyzed their protocol in terms of access to their external network channels. Unfortunately, the reality is that unauthorized access to the internal network of vehicles is still a possibility. If your vehicle’s speed and direction can be controlled – that’s a major problem.

Inside Car Security

Let’s explore a bit inside the vehicle. Within the vehicle there are several ECUs (Electronic control units). The ECUs will communicate with each other and hence the vehicle is able to fulfill a variety of functions. The ECU network is basically a miniature version of a corporate network. Within the corporation there are servers set to handle important tasks and then there are some individual computers that hold less significant roles as well. Within the servers, there are those that will handle external communication and then servers that have no access to the external system, only internal. So in order to manage and protect the multiple methods and devices that are required for communication, corporations long ago set up firewalls as a security measure.

In computer security, between the external and internal firewall, a DMZ (demilitarized zone, or sometimes referred to as a perimeter network) is set up. This allows for a zone/sub-network that adds an extra layer of security.

Now, this is also necessary within an automobile’s network for car security. Any units responsible for communicating with external systems as well as the internal network’s ECU should be placed within the DMZ so that it can have that extra layer of protection. If this had been the case,  incidents like the Jeep Cherokee hack could have been avoided. Even if the external channel had been hacked and the external firewall had been incapacitated, it would have had an extra layer of protection within the internal firewall.

inside car security for a smart car

Up to the Application Layer

But it’s not enough to simply put a firewall within the internal system. A firewall that operates on the network level will give access depending on the client or the server side’s port. It’s not as easy to create policies. Hence creating loopholes for hackers to get around is becoming easier. Because of this, companies like Argus Cyber Security, Symantec, and Penta Security have developed technology to analyze up to the application layer in order to detect possible intrusions and attacks.

These companies take an extra step. They don’t simply stop at deciding which ports to allow and which to block. They go further into analyzing the influx of traffic to see whether an attacker is trying to get into the automobile’s system or not. Through systems like IDS/IPS and even a WAF (Web Application Firewall), companies agree that these extra security measures are necessary.

If the evolution of connected cars continues as it has, then the different connections within the system will also change. And this will give further opportunities for hackers to find a crack within the system. Hence, overseas as well as domestically here in Korea, a V2X (Vehicle-to-Anything) testbed is underway. Utilizing V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure) communications to come up with different scenarios, with elliptic curve cryptography (the next generation of public key cryptography) they seek for methods to protect any V2V and V2I communication.

The conclusion is this: to protect cars from the threat of hackers and attacks, priority needs to be placed on installing a firewall. This will protect the internal network of the car, especially the application level of the network. The firewall needs to have the ability to detect and analyze the attacks.

Preparing for a New Era of Security

This idea not only applies to car security but to the wider scope of IT security. Simply applying one or two security measures to a device or a server does not mean that everything is secure. Far from it. IT is always changing and adapting to fit the needs of the current era, so automobile technology and automobile security will continue to become increasingly complicated.

Therefore, it’s extremely crucial that we prepare from preparing a car security system all the way from preparation to installation to keep the smart vehicles safe on the road.


This blog post was adapted from an article written by Dr. Sang Gyoo Sim at Penta Security’s IoT Convergence Lab regarding the security issues in smart cars. Find the original article in Korean here

smart car mercedes benz with speed and meter black

The Smart Car Trend (Part 1): A New Era?

Some recent keywords that have garnered attention in the IT industry are connected car, smart car, or IoT.

Cars have come a long way. From being a vehicle or method of transportation, to being “connected” on a network… now cars are becoming “smarter” and hence many corporations are leaning towards building a more intelligent vehicle.

What makes a smart car so “smart”?

When it comes to a device being described as “smart,” most people will probably think of the smartphone.  Rightfully so, as it’s the same concept. Before it was simply a method of communication, but we were eventually able to connect the device to a network – so what sets apart the smartphone from a phone that’s merely connected to a network?

A smartphone goes past being a method of mere communication. It allows the user to customize and execute software. It differs vastly from the phones of the old days. With that in mind, let’s go back to the idea of a smart car. A smart car is “smart” because not only is it connected to a network, but the software can be customized and executed the way the user wants, making it a much stronger platform. More and more automobile makers  have been leaving the idea of the first generation of cars and leaning towards this new generation of smart, connected cars.

In fact, the lines of code in software for automobiles surpasses the number of code for combat planes, commercial planes, heck – even Facebook – with over 100 million lines of code. Cars are taking over the industry. In fact, the running joke of this year’s Consumer Electronics Show (CES) in Las Vegas was that it should be called the “Car Electronics Show” with the number of automobile companies that showed up with new technology in hand.

So if you’re going to remember anything about the rising trend of smart cars, here are the top three must-know facts within this trend:

First, automobile companies are going to the cloud.

BMW featured the Open Mobility Cloud at this year’s CES, connecting the vehicle with a person’s schedule and tasks. So not only is your car a vehicle – it now houses features of a smartphone as well.

Second, smart car/home network connections are all the rage.

For example, recently Volkswagen and LG agreed to a join development after LG revealed its smart refrigerator at CES in January. Why a refrigerator? It’s a brilliant execution, as a refrigerator is widely regarded as the family hub, the center of a home network. As a device that is never turned off and is used constantly by family members of various ages, the idea of connecting it to the smart car was a strategic move.

Third, maps are becoming crucial to the smart car service platform.

Many automobile companies have acquired mapping corporations, especially as the technology to map out locations on-demand have been developing. This is a smart move as licensing fees on third-party map use for navigation could be exorbitant. After all, the first thing one thinks of when they think of cars being “connected” is location services and GPS.


So the conclusion is that the connectivity in cars is becoming more widespread and more intelligent. But the second and perhaps more important question is, what’s the concern over security of the vehicle? Stay tuned as in Part 2 we’ll explore the growing concerns over breaches of automobiles and how that can mean catastrophic consequences for society.


This blog post was adapted from an article written by Dr. Sang Gyoo Sim at Penta Security’s IoT Convergence Lab regarding the security issues in smart cars. Find the original article in Korean here