Common Network Vulnerabilities and their Types

Network vulnerability can be a major headache for companies and organizations of all sizes. And with cybercrime on the rise, network vulnerabilities have never been more important to understand. By understanding the different types of network security vulnerabilities and how they can be exploited, you can take steps to shore up your defenses and protect your organization.  

In this blog post, we’ll be discussing the most common types of vulnerability in network security along with examples. By the end, you’ll be armed with all the information you need to protect your business from cybercrime. 

What is Network Vulnerability?

A network vulnerability is a weakness in the network’s computer systems that can be exploited by attackers. These network security vulnerabilities can exist in the network infrastructure, the operating system, the applications or the users themselves. 

Attackers can use the vulnerabilities to gain access to systems and data, or to disrupt network service. 

Let’s find out the most common network security threats and their types in the next sections. 

Common Network Vulnerabilities and Threats

While there are many types of vulnerability in network security, some are more common than others. In this section, we'll go over some of the most common threats to your network security.

But first, it's valuable to emphasize at this point that the importance of network security cannot be overstated. Many organizations view their network as an impenetrable fortress far away from security breaches, but the truth is that it can be surprisingly easy to hack into a network when the attacker knows where to look, and many indeed know. 

Network vulnerabilities in general can run into hundreds. But there are a couple that are quite common, yet also happen to be the most overlooked or underrated. 

Here we share the top 5 most common network vulnerabilities that all organizations plus their teams really need to be wary of. 

1. Ransomware

Ransomware is a type of malware that encrypts data on a victim's computer and holds it hostage until a ransom is paid. 

The victim is given a countdown timer and often threatened with severe security consequences such as data deletion if the ransom isn't paid on time. Ransomware is particularly insidious because it can take over an entire network, encrypting files on every computer on the network. 

Ransomware is one of the most scary of the common threats to network security and costs businesses worldwide millions in damages. It’s also embarrassing. 

To protect your business from ransomware, make sure to install anti-virus software and keep it up to date, back up your data regularly, and restrict access to sensitive data to only authorized users. 

2. DDoS

DDoS stands for Distributed Denial-of-Service (DDoS). A DDoS attack is when a hacker sends overwhelming amounts of traffic to a website or server, so much that it can no longer handle legitimate requests. 

The malicious attacker literally floods a network with so much traffic that it can't function. This can be done in a number of ways, but one common method is to send a huge number of packets to the target server. The server can't keep up with the demand and eventually crashes under the load.

The first ever known DDoS attack surfaced in 1996. The victim was Panix, an ISP that is considered the oldest provider in New York. Panix was taken offline for many days by DDoS weapon SYN food. SYN food is known to exploit vulnerabilities in a server’s TCP three-way handshake, rendering the server unresponsive. 

Vulnerabilities that allow DDoS attacks can take a website offline or make it so slow that users can't access it. There are several ways of preventing network vulnerabilities that invite DDoS attacks, including using a third-party service and increasing your bandwidth. 

3. IoT vulnerabilities

The use of IoT devices is increasingly becoming commonplace, and herein lies a major threat to networks as criminals look out to take advantage of vulnerabilities in IoT installations. 

Hackers can insert malicious code into an incredibly large number of vulnerable IoT devices, directing them to stream packets and ambush an organization’s network with damaging attacks. 

One of the most memorable attacks that exploited IoT vulnerabilities is the Mirai botnet attack that occurred in 2016 and left a trail of IoT driven damage. We’ll get into this in detail under types of vulnerabilities in the next section. 

4. Phishing

Phishing is one of the most common network attacks and sits atop among the most notorious vulnerabilities that you must watch out for. Attackers exploit the system by using fraudulent emails or websites to steal personal information from users. 

A report by IBM indicates that phishing is the top vulnerability exploited by attackers, hitting even top global brands like Apple, Google and Microsoft. The report found that 50% of targeted victims actually clicked on phishing campaigns, exposing their organizations to costly threats. 

Attackers can exploit phishing vulnerabilities to steal your teams’ login IDs (usernames) as well  as passwords. A good example of a phishing attack is when a user opens what appears to be legitimate email. But hidden inside the deceiving email is a malware code that logs out the user as soon as they open it. Once the user logs back after being logged out, the malware captures their keystrokes. These keystrokes are all the criminals need to get  the usernames and passwords. 

5. SQL injection

Another most common network vulnerability is SQL injection. Attackers use SQL injection to exploit vulnerabilities in a database, allowing them to access and manipulate data.

In this attack, the hacker sends specially crafted SQL statements to the target database in an attempt to extract data or execute commands. They may even be able to gain control of the entire database server. They can steal information such as passwords and credit card numbers, or even take over full control of the database. 

Impact of SQL injection 

SQL injection can have the following impacts:

  • Attackers can enter the database servers with OS permissions and gain access to sensitive systems within the network.

  • Attackers can compromise or introduce dangerous foreign data to the database

  • Attackers can get hold of credentials, impersonate legitimate users and use their privileges to inflict damage to the network. 

  • Attackers can delete records in the database or even get rid of entire tables.

There are a number of ways to protect your database from vulnerabilities that criminals can exploit to introduce SQL injection attacks. One is to use parameterized queries, which are queries that are prepared ahead of time and don't allow for user input. 

You can also use stored procedures, which are routines that can be executed from within the database itself. These procedures help to protect against SQL injection attacks by limiting the types of data that can be accessed and processed. 

Types of vulnerabilities in network security

Network security vulnerabilities and threats come in many different shapes and sizes, but can generally be divided into three main categories: hardware vulnerabilities, software vulnerabilities, and human error vulnerabilities. 

They all have the potential to cause serious damage to your business. One of the best ways to safeguard your network against the most complicated vulnerabilities is to use professional network support services

All manner of vulnerabilities are likely to fall into the following three most common types of threats in network security

1. Hardware vulnerabilities

Hardware vulnerabilities are flaws in the physical system that attackers can exploit. The attacks can be executed remotely or by physically accessing the hardware system.  

Any loophole that can permit malicious code into the physical network and destroy devices inherently falls under network security threats and vulnerabilities of the hardware type. 

These flaws can exist in the design or in the manufacturing process. Attackers can exploit hardware vulnerabilities that allow full system control to gain access to sensitive data or to take control of the system. 

Hardware vulnerabilities are a major concern for companies and organizations that rely on computer systems for critical operations. 

Here are a couple forms of different hardware vulnerabilities and the damage they can cause. 

  • Directory traversal:  Occurs as a result of flaws in old or obsolete routers. These flaws make it easy for criminals to take over the routers and use them to extract important administrative data. 

  • Rowhammer: Rowhammer vulnerabilities affect DDR DRAM devices, where a memory can be accessed many times and cause bit flips within adjustment rows. This then allows hackers to interfere with the values of the memory’s bit. 

  • Foreshadow: Foreshadow is a vulnerability that is associated with Intel CPUs. Hackers exploit this vulnerability to gain access and get away with sensitive data from the L1 data cache of the CPU. 

Hardware manufacturers are always working to reduce the number of hardware vulnerabilities in their products, but these vulnerabilities will always be a headache. 

Example: The Mirai botnet attack, 2016

The best example of where hardware vulnerabilities can be exploited to large scale damage is the Mirai botnet attack that happened in October of 2016, the largest of its kind. It left an imprint of destruction, but not without a silver lining - a wake-up call for the security community. The attack was made possible by hardware vulnerabilities in IoT devices, which the attackers exploited to create a massive DDoS (distributed denial of service). 

The Mirai botnet, a new weapon at the time, trained its guns at the networks of Dyn, an American DNS service provider that was later acquired by Oracle. The damage was far and wide, affecting major sites including, Netflix, GitHub, Spotify, Quora, Reddit, Twitter and indeed Dyn’s own website. 

The attackers infected a network of vulnerable IoT devices with a special kind of malware named “botnet”. They then coordinated the infected devices to bombard the servers of Dyn with traffic until they collapsed under the strain. 

Over 500,000 devices infected

The Internet of Things (IoT) concept was not nearly as obvious back in 2016 as it is now. It was a little new then, a technology largely at hype phase which only a few had a hang on. This made the Mirai attack even more intriguing. 

Intriguing in the sense that while other botnets normally originated from a network of computers, the Mirai botnet caught companies flat footed as it was largely driven by IoT devices: DVR players, air-quality monitors, home routers, digital cameras and more IoT. Conservative estimates show that Mirai infected over 500,000 vulnerable IoT devices at its peak. 

These kinds of attacks are only going to become more common as more and more devices are connected to the internet. So, what can you do to make sure your network is secure? Make sure you're patching your devices regularly, using strong passwords and changing default settings. You should also be aware of which devices in your network are susceptible and take steps to protect them. 

How to prevent hardware vulnerabilities

  • Review hardware vendors: Seek to understand the security processes of all your hardware vendors. Do they have a good hold of their component suppliers? What is their security history? These details will help you to verify that the vendors will not supply you with vulnerable hardware as a result of their negligence. For example, ensure the manufacturer performs thorough laboratory tests for Trojan Circuits prior to deploying the final product. 

  • Hardware Firewall: Deploy the right hardware Firewall for your hardware infrastructure depending on what devices you want to protect as well as the broadband router that you are using. Your router should also have an inbuilt Firewall, so please ensure that it is always active. Large organizations are better off using business networking Firewall.  

  • Shut down: Always Shut down your servers whenever they are  not in use for a considerable period of time like overnight. In other words don't leave your web server running even when it's not in use. Unless your organization is in the business of providing internet-based services, it makes security sense to switch off your hardware during the time that it is not in use. Many businesses have the habit of leaving their machines on, a vulnerability that can lead to serious damage. Timely shut downs will break any connection that attackers may have established to your network, throwing them off balance and suspending their crooked operation. 

2. Software vulnerabilities

A software vulnerability is a flaw in the network system’s software architecture that can allow an attacker to gain access and compromise the system. The vulnerabilities can be due to many factors and mostly in the design and source code architecture. 

By software here we mean any software that you use in your network systems, from the operating systems to other additional softwares that you utilize. The most common software security loopholes include injection flows, broken access control, missing or broken authentication, misconfiguration, bugs, and buffer overflow. 

Once an attacker succeeds in gaining access to the software that runs your network system, they can easily manipulate crucial data, damage it with botnets like in the example of the Mirai botnet DDoS, plant malware, or install a backdoor. Some attackers can also penetrate one network host and use it to cause havoc in more hosts running in the same network. 

Top software vulnerabilities

The US Cybersecurity and Infrastructure Security Agency lists the top software vulnerabilities or cyber attacks that are routinely exploited from time to time. 

Below is a summary of the top software vulnerabilities that were exploited across 2021.

Vendor and Product

Name of Vulnerability

Attack Action Type

Apache Log4j


Remote code execution (RCE)

Microsoft Exchange Server


Elevation of privilege

Microsoft Exchange Server



Microsoft Exchange Server


Security feature bypass

Microsoft Exchange Server



Microsoft Exchange Server



Microsoft Netlogon Remote Protocol (MS-NRPC)



Source: US Cybersecurity and Infrastructure Security Agency

Example: Aids Trojan by Dr. Joseph Popp

A  good example of a software vulnerability was exposed by the first ever ransomware known as the Aids Trojan Horse, unleashed in 1989 by one Dr. Joseph Popp, a biologist. Joseph sent infected floppy diskettes to hundreds of innocent people.The title of the diskettes was so appealing, but the contents did the exact opposite. The title read, “Aids Information Introductory Diskette”. 

As soon as a user inserted the diskette into their computer and played it, it automatically replaced the file AUTOEXEC.BAT and started counting the computer’s number of boots. Once the number of boots clocked 90, the ransomware would then hide directories and encrypt all file names on the hard drive. This would render the entire system impossible to use.

Once the computer was unusable, the now “lost” victim would be instructed to renew their operating software license by sending $189 to an address in Panama, apparently belonging to an organization called ‘PC Cyborg Corporation”. Ironically, the decryption key was right there in  the Trojan's code. 

As you might have guessed by now, Dr. Joseph Popp collected some easy profits with the “clever” ransomware. He was eventually prosecuted, processed for trial, but was unfortunately declared mentally unfit to go through the trial. He concluded the mischief by promising to donate part of his profits towards research efforts into Aids.

How to prevent software vulnerabilities

  • Train developers: Invest in training your developers to write impenetrable code, at least for the most critical areas if not everywhere in the software ecosystem. A base level security masterly will go a long way to defend your organization against catastrophic software vulnerabilities. 

  • Scan code: Use automated code scanning tools to scan your entire code for vulnerabilities. While no tool or combination of tools can discover each and every vulnerability, investing in code scanning will make a significant contribution to your network security. 

  • Testing: Test your software with code analysis tools to establish and quickly get rid of vulnerabilities. 

  • Regular updates: Make a point of updating your software regularly. Outdated software is a glaring vulnerability that attackers can discover and exploit to your downfall.

  • Antivirus: Purchase and install the right antivirus software to protect your network against unauthorized code or programs. New viruses come up all the time, so it's important to ensure that the antivirus is always running whenever your systems are on. In addition, perform regular virus scans to keep your system free of viruses. 

3. Human error vulnerabilities

Human-based vulnerabilities are those that are caused by human error. This can be anything from clicking on a phishing email to leaving your computer unlocked when you walk away. 

A World Economic Forum Report reveals that indeed human error is the ultimate cause of nearly all cybersecurity vulnerabilities, accounting for an astonishing 95%. So you can clearly notice how serious this vulnerability can get. It means if you can work on human errors within your organization, you can somehow prevent at least 9 out of 10 cyber threats. 

Human errors can be task based or decision based.Task based errors are those where a user makes simple but costly errors as result of negligence, fatigue, or insufficient skills. Decision based errors come about as a result of faulty decisions due to limited knowledge, scant information or inaction. 

Example: Google and Facebook

The best example of the kind of attacks that can take advantage of human vulnerabilities is phishing. Big companies such as Google and Facebook have fallen victim to human error vulnerabilities and lost millions. The scammers took advantage of a vulnerability in the two companies’ sourcing systems. Both Google and Facebook were using the services of  a hardware vendor based in Taiwan, known as Qanta. The phishers released fake invoices to Google and Facebook. The invoices appeared just like the usual original invoices from Qanta, but of course they were all pure impersonations that employees of the two companies failed to detect. Google and Facebook, giants in the tech space, paid the phishers to a tune of US$100 million. Reason? human error. The main perpetrator of the scheme was eventually tried and surrendered US$49.7 million

If the big corporations can fall prey to such seemingly simple vulnerabilities, no organization can claim to be safe. The best way to protect yourself from phishing attacks is to be vigilant and NEVER click on links or open attachments from unknown sources. Always make sure the website you're visiting is legitimate and has a secure connection (look for the HTTPS lock in your browser's address bar). You can also install anti-phishing software to help protect you from these attacks. 

How to prevent human vulnerabilities: 

  • Training: Be diligent about training your employees and make sure they understand the importance of security.

  • Protocols: Have protocols in place for when an employee makes a mistake. For example, implement a protocol system that automatically locks the computer after a set amount of time or requires a password to unlock it.

  • Tools: Use tools that alert your employees to double check certain actions where there is threat of high network risks. A good example is when they receive emails from vendors like the case of Google and Facebook where scammers faked emails from a supposed vendor and got paid millions. Use systems and structures that help employees to take each high impact communication through a strict verification system.

Network Vulnerabilities: Conclusion

To ensure network security, it's important to be aware of the major types of vulnerabilities that can exist. Hardware vulnerabilities are caused by a flaw in a physical device, software vulnerabilities are caused by a flaw in the software code, and human error vulnerabilities are caused by mistakes made by humans. 

You can protect your network against these vulnerabilities by using security tools like firewalls and intrusion detection systems, utilizing the services of network security providers, and by training your employees on how to protect against these threats.

Network Vulnerabilities FAQ

What are the three 3 types of network service vulnerabilities?

The three 3 main types of network service vulnerabilities are hardware vulnerabilities, software based vulnerabilities and human error vulnerabilities. Of these three, the human error type of vulnerability accounts for the majority of threats. Networks can be exposed to a variety of vulnerabilities, which can expose your data and systems to network security risks. By understanding the most common vulnerabilities and taking steps to mitigate them, you can help reduce the risk of a security breach.

How do you find network vulnerabilities?

The first step is to identify the systems and network devices that are connected to your network. Once you know what's on your network, you can start looking for vulnerabilities. You can do this manually or use a scanning tool. A vulnerability scan is a process that checks your devices and systems for vulnerabilities. It compares the results against a database of known security flaws. If a system is found to be vulnerable, you can take steps to fix it.

What is network vulnerability testing?

Network vulnerability testing is the practice of reviewing and analyzing a network’s system for potential existence of vulnerabilities. It is an important process that network administrators run to evaluate the network in order to identify threats early enough before attackers can exploit them.