Common Types of Network Security Vulnerabilities

Network vulnerability is a weakness or flaw in software, hardware, or organizational processes that can be exploited by attackers to gain unauthorized access, perform malicious activities, or steal sensitive data.

Nonphysical network vulnerabilities are weaknesses in a computer network’s software or data components. For example, an operating system (OS) might be vulnerable to network attackers if not updated with the latest security patches. This could propagate a virus to the host it’s located on and potentially the entire network.

Physical network vulnerabilities refer to the physical aspects of a network’s security system that could potentially be exploited by malicious entities. These vulnerabilities usually involve direct contact or interaction with the network’s hardware. For example, Unauthorized physical access to a server room can lead to devasting breaches.

What Are The Different Types Of Network Vulnerabilities

1. Malware is malicious software, such as Trojans, Viruses, and Worms, installed on a user’s machine or a host server.

2. Social engineering attacks fool users into giving up personal information such as usernames or passwords.

3. Outdated or Unpatched software exposes the systems running applications and potentially the entire network.

4. Misconfigured firewalls / operating systems that allow default policies or enabled.

01. Malware (Malicious Software)

Malware is malicious software, which refers to any program designed to disrupt, damage, or gain unauthorized access to a computer system or network. The use of malware to exploit network vulnerabilities continues to rise, hitting an all-time high of around 1.2 billion malicious programs and potentially unwanted applications (PUA).


Systems infected with malware will present with symptoms such as running slower, sending emails without user actions, randomly rebooting, or stating unknown processes.

Malware can infect a system, exploiting vulnerabilities and user behaviors. Here are some common infection vectors:

1. Phishing Emails: Malicious actors send emails posing as legitimate entities or organizations, tricking users into clicking on
malicious links or downloading infected attachments. Once opened, malware can infect the system or network.

2. Drive-by Downloads: Visiting compromised or malicious websites can automatically initiate malware downloads onto the user’s system without their knowledge or consent. Outdated software or browser vulnerabilities are often targeted for such attacks.

3. Malicious Software Downloads: Users might unknowingly download malware-infected software from untrusted or unofficial
sources. These downloaded applications or files may appear legitimate but contain hidden malicious code.

4. USB and External Devices: Malware can spread when infected USB drives or other external devices are connected to a system. Auto-run features or vulnerabilities in the system can trigger malware execution.

5. Software Exploits: Malware creators can exploit vulnerabilities in operating systems, applications, or plugins to gain unauthorized access and install malware.

6. Social Engineering: Attackers manipulate users through social interactions, tricking them into executing actions that lead to malware installation. This can include deceptive pop-up windows, fake alerts, or fraudulent software updates.

7. File-sharing Networks and Pirated Software: Illegitimate file-sharing platforms or downloading pirated software expose users to the risk of downloading malware-infected files.

The most common types of malware include:

  • Viruses
  • Worms
  • Trojans
  • Ransomware
  • Logic Bombs
  • Keyloggers
  • Adware & Spyware
  • Bots / Botnets


A virus is the most common type of malware attack. Viruses replicate and spread across devices without the user’s knowledge. They often corrupt or destroy data and impact system performance. Viruses can be spread from one system to another via email, instant messaging, website downloads, removable media (USB), and network connections.

Some file types are more susceptible to virus infections:- .doc/.docx, .exe,
.html, .xls/.xlsx, /.zip.
Viruses typically remain dormant until they
spread onto a network or several devices before delivering the payload.


Like viruses, worms are self-replicated malware that spread rapidly across the network without human intervention. They exploit vulnerabilities in computer software to infect connected devices, infecting and consuming network bandwidth. Worms are commonly used against email, web, and database servers. Once infected, worms spread quickly over the network



Trojan horse programs are malware disguised as legitimate software. They hide on your computer until they are activated. Trojans can allow attackers to gain unauthorized access, steal sensitive data, or execute remote commands on infected systems when activated.

Trojans are commonly disseminated through email attachments, website downloads, and instant messages. Unlike computer viruses and worms, Trojans cannot self-replicate.



Ransomware is malware that uses modern encryption algorithms to make money for cybercriminals. It locks users out of their systems or denies access to data, encrypts user files, and requires payment within a time frame and often through a digital currency like Bitcoin.

The infections usually occur via malicious email attachments, links, or exploit kits. If not mitigated promptly, ransomware attacks can lead to data loss, financial loss, or disruption of services. Current estimates of the Baltimore ransomware attack are up to $18 million in damages.

Logic Bombs

Logic bombs are dormant pieces of code that trigger a malicious action when specific conditions are met, such as on a specific date/time. Viruses and worms often contain logic bombs to deliver their payload (malicious code) at a pre-defined time or when another condition is met.

The damage caused by logic bombs varies from changing bytes of data to making hard drives unreadable, causing system crashes, data breaches, or disrupting critical operations when activated.


Keyloggers secretly record every keystroke on a target device and send logs to the threat actor. While there are use cases for employers using keyloggers to track employee activity or by parents to supervise their children’s internet usage, they’re mostly used to steal passwords and other sensitive data.

Adware & Spyware

Adware and spyware are both unwanted software. Adware is designed to serve unwanted advertisements on screens within a web browser of infected systems. it’s usually quietly installed in the background when downloading a program without your knowledge or permission. While harmless, adware can be annoying for the user.

  • Spyware
    is a type of malware designed to access and damage your computer. It collects user information such as habits, browsing history, and personal identification information. Attackers may then sell your personal information to advertising companies or data collection firms, gain unauthorized access to your bank account details or engage in identity theft.
  • Adware and spyware impact system performance, compromise privacy and may lead to identity theft or financial loss.



Rootkits are backdoor programs that allow unauthorized access to and control over an infected system without the user’s knowledge. They often modify system files or kernel components, making detection and removal difficult. Rootkits are typically deployed through software exploits, infected downloads, or phishing attacks.

02. Social Engineering Attacks

Social engineering attacks have become a popular method for threat actors to bypass authentication and authorization security protocols and gain access to a network.

These attacks have increased significantly in the last five years, becoming a lucrative business for hackers. Internal users pose the greatest security risk to an organization, typically because they’re uneducated or unaware of the threat. Accidentally downloading an attachment or clicking a link to a website with malicious code can cost thousands in damages.


The most common types of socialengineering attacks include:

  • Phishing emails
  • Spear phishing
  • Whaling
  • Vishing
  • Smishing
  • Pharming
  • Tailgating
  • Shoulder surfing
  • Dumpster diving

Phishing Emails

A phishing email scam is an online threat that appears as fraudulent emails that resemble legitimate ones and often masquerade as reputable organizations. They typically aim to trick recipients into providing personal or financial information, such as passwords or credit card details, by clicking malicious links or downloading attachments.


Spear Phishing

Spear phishing is similar to phishing in that it attempts to trick a user. This form of phishing is highly targeted and personalized. Attackers conduct extensive research to create emails tailored to specific individuals or groups. By using personal information obtained through various means, the attackers increase the chances of success.


Whaling uses deceptive email messages to target high-level decision-makers, such as CEOs, CFOs, and other executives. These individuals can access highly valuable information, including trade secrets and passwords, to administrative company accounts.

The attacker sends emails on issues of critical business importance, masquerading as an individual or organization with legitimate authority. For example, an attacker may send an email to a CEO requesting payment, pretending to be a company client.

Vishing (Voice Phishing)

Vishing, the combination of voice and phishing, is a phishing attack that takes place over the phone, typically a VoIP (Voice over IP) line. Threat actors can use tools specific to VoIP systems, hacking their auto-dialers to send robo messages from a spoofed VoIP address.

Attackers may pretend to be from a trusted organization and manipulate individuals into revealing confidential information or performing certain actions.


Smishing is a cyber-attack that uses SMS text messages to mislead its victims into providing sensitive information to a threat actor. The threat actor may also embed a short URL link into the text message, inviting the user to click on the link, which, in most cases, is a redirect to a malicious site.


Pharming involves manipulating the domain name system (DNS) to redirect users to fake websites without their knowledge or consent. Pharming occurs when code is installed on the computer that modifies the destination URL to the attacker. Pharming can result in the loss of data and credit card information or lead to identity loss.


Tailgating is a simple social engineering attack involving an unauthorized individual gaining access to a restricted facility by following a legitimate user through a security checkpoint. This method exploits a fundamental aspect of human nature ─ being polite and holding the door for others. Threat actors blend in and bypass the security measures designed to keep intruders out by taking advantage of this social norm.

Shoulder surfing

Shoulder surfing is a type of social engineering that involves obtaining personal or private information through direct observation. It’s very easy for a threat actor to casually glance over an employee’s shoulder to view their monitor.

Users should always be aware of their surroundings when using login names and passwords or accessing sensitive data. This is especially true when using a computer, smartphone, or ATM in a crowded area.

Dumpster Diving

Attackers engage in dumpster diving by searching through discarded physical documents to find confidential information. By inspecting trash bins or dumpsters, they gather information that can be used for identity theft, impersonation, or other malicious purposes.

03. Outdated Or Unpatched Software

An outdated or unpatched software vulnerability is a common type of network security that refers to a weakness or flaw in computer software that can be exploited by attackers. This vulnerability occurs when software is not properly updated or patched to address security issues discovered after its release.

Several types of network security vulnerabilities can arise due to outdated or unpatched software:

    • Remote code execution – This vulnerability allows an attacker to execute arbitrary code on a target system remotely, without any user interaction.
    • Denial of Service (DoS) – Outdated or unpatched software often contains vulnerabilities that can be exploited to launch DoS attacks. These attacks overwhelm a system or network, rendering it unable to perform its intended function and causing service disruptions or loss of availability.
    • SQL Injection – This vulnerability occurs when a web application fails to sanitize user inputs, allowing an attacker to inject malicious SQL queries. An attacker can manipulate these queries to bypass authentication, retrieve sensitive information, modify or delete data, and potentially gain control over the database.
    • Cross-Site Scripting (XSS) – XSS vulnerabilities arise when a web application fails to properly validate user-provided data. This allows attackers to inject malicious scripts into websites that are subsequently executed by users’ browsers. This can lead to session hijacking, cookie theft, or website defacement.
    • Privilege Escalation – Outdated or unpatched software often includes security vulnerabilities that enable attackers to escalate their privileges from a user with limited access rights to a privileged system account. This can give the attacker unrestricted access to sensitive data or critical system resources.
    • Authentication Bypass – This vulnerability allows attackers to bypass authentication mechanisms and gain unauthorized access to a system or network.

Organizations should regularly update and patch all software applications in their network environment to mitigate the risks associated with outdated or unpatched software vulnerabilities.