6 Vulnerability Types You Need To Know

A vulnerability is any flaw or weakness within a technology system.

Addressing vulnerabilities is a starting point for cybersecurity, because it is these weaknesses that cybercriminals and other threat actors can exploit to gain unauthorized access to a network, information assets, and/or software applications.

A recent example of a vulnerability is CVE-2024-6387, nicknamed "regreSSHion". This flaw, discovered in summer 2024, exposes Linux environments to remote unauthenticated code execution. The potential impact of this vulnerability is far-reaching, perhaps affecting countless servers and infrastructure components across the globe.

For any organization today, there are plenty of vulnerabilities, both known and unknown. By knowing where and how vulnerabilities can exist, you can get ahead of them. So, in this article, we'll look at the six most common, or important, types of vulnerabilities. First, let's set the stage with some clarity around threats, vulnerabilities, and exploits. 

Overview: vulnerabilites, exploits, threats, risk

When it comes to cybersecurity, the terms vulnerability and threat are interconnected but distinct, and always related to risk.

• First, a vulnerability is a flaw or weakness in the system. This exposes your organization to threats. For example, software having a security flaw is a vulnerability.
  
• A threat is a particular malicious or negative event that exploits a vulnerability. A threat may be, for example, hackers conducting some cybersecurity attack, or an insider who either accidentally or intentionally causes harm.
• The risk is the potential for and damage when a threat does occur. 

Another closely related term is exploit. A cybersecurity exploit is any technique that attackers may use to take advantage of a vulnerability. Often, an exploit is delivered via a piece of code built to target that vulnerability. Attackers may use the following types of exploits to take advantage of a system's weaknesses.

• Remote exploits: Attackers can access and attack the system remotely from a distance, using the internet, without requiring physical access.
• Local exploits: Attackers require a system's physical access, where they exploit a weakness to gain further control.
• Zero-Day exploits: These target vulnerabilities are unknown even to the software vendor, thus potentially dangerous until/unless a fix or patch is released to fix the vulnerability. 

To prevent these exploits, organizations need to promptly implement security patches, use detection systems against intruders and regularly monitor for unusual activities.

Impact on security

We require security measures because of the presence of a threat. (If there is zero threat, then any vulnerabilities are fine to exist, at least in theory.) Security measures aim to protect against threats, the primary cause of harm.

Vulnerability creates a scope for a threat to exploit a system — that's why a crucial part of any security strengthening is addressing vulnerabilities. This is the practice of vulnerability management. 

Vulnerability management, summarized

To be clear, a security vulnerability usually exists in one of two ways:

• Resulting from a given design, such as a coding or hardware design flaw built into the product and its updates. 
• Emerging from how a technology is deployed within a business process, perhaps incorrectly or incompatibly with other systems.

Considering the incredibly vast and distributed nature of technology systems in an enterprise IT environment, many business organizations employ automated vulnerability management solutions to defend against cyberthreats. The process typically involves:

1. Vulnerability discovery (via vulnerability scanning)
2. Categorization and prioritization
3. Resolution
4. Reassessment and reporting.

For this article, we’ll focus on the first phase of the vulnerability assessment and management process — discover — by understanding different types of vulnerabilities that may exist within a business.

(Related reading: vulnerability management introduction and CVE, common vulnerabilities and exposues.)

Most common vulnerability types

So if a vulnerability is any flaw or weakness, that means there’s probably a lot of them in all of your digital and hardware systems. Knowing these sox types will help you sort and prioritize them.

Type 1. Software vulnerability

This type of vulnerability refers to the flaw within the software products. Software vulnerabilities tend to occur due to:

• Programming errors such as SQL injection and cross-site scripting.
• Design flaws such as a failure to adequately authenticate a user request.

A cybercriminal can exploit these vulnerabilities to install a malware payload or backdoor into the technology stack. The software may continue to function with logical correctness despite the vulnerability — allowing cybercriminals to remain under the radar after exploiting the vulnerability.

Type 2. Network vulnerability

Network vulnerabilities can include any vulnerabilities within the software, hardware, and processes that govern:

• The flows of data workloads
• User traffic
• Computing requests within the IT networks.

These vulnerabilities range from the hardware components in the physical layer and all the way up the stack to the application layer of the OSI model.

The extensive nature of the technologies that constitute an IT network makes it challenging to keep track of networking vulnerabilities: every hardware product and every software service is from a different vendor and is therefore exposed to its own set of security risks. Even when all device software and firmware are maintained and up to date, the network fabric may be vulnerable to unauthorized access due to misconfigured firewall and traffic routing.

Type 3. Configuration & process vulnerabilities

Misconfigurations can expose a system — even when the individual software and hardware products function without an exposed security vulnerability.

The products may be configured with default administrative credentials, which may be already known to a cybercriminal. The default security settings may fail to encrypt sensitive data workloads automatically, which means that any leaked data is also vulnerable to:

• Modifications
• Trade secrets
• IP theft

Another aspect of misconfigurations deals with the process-level risk exposure of the system. This can come from the TCP/IP protocols, traffic workflows, and authentication systems in place to ensure that the network behaves as expected.

Misconfigurations may force the network traffic to violate an explicit or implicit security policy.

Since no individual network node or component behaves unexpectedly at this point, engineering teams rely on statistical analysis to determine whether the network as a whole complies with the assigned security policies.

Type 4. Insider threats

According to research, the human element is responsible for 95% of all cybersecurity incidents. And not all of those human elements are external to your organization. 

The vulnerability of an insider threat is a challenging case: at the outset, an employee is trusted with sensitive business information and access to mission-critical technology systems. If the employee becomes dissatisfied or disgruntled and intentionally chooses to harm their organization, the risk exposure comes down to two things:

• The access privileges assigned to them
• Their ability to gain unauthorized access

The other type of insider threat stems from either accidents, negligence, or lack of security awareness of the employees handling sensitive business information.

There is no well-defined method for uncovering the malicious intent of a disgruntled employee. Similarly, predicting the security negligence of a trusted team member is also challenging. However, organizations can minimize this risk exposure through various measures. These include:

• Adopting strong security access controls following the principle of least access privilege.
• Encrypting sensitive data assets.
• Real-time monitoring and observability of computing requests pertaining to network access and data modification.

Type 5. Physical vulnerability

In the context of cybersecurity vulnerabilities, physical security is particularly relevant to cloud infrastructure vendors and large organizations operating in-house data center systems. A physical vulnerability may include:

• The ability to access server rooms
• Camera blind spots
• Inadequate documentation
• Recording of physical activities performed in the data center, such as replacing storage devices

However, any insider threat within the physical office premise, or theft or loss of a BYOD (Bring Your Own Device) device can expose security risks to the organization. Consequently, to address physical vulnerabilities, organizations must enforce strict policy controls governing the use of business information on BYOD devices. They should also regulate access to corporate apps, services, and networks from outside the organization's physical premises.

Type 6: Buffer overflow vulnerability

When a program goes beyond its buffer handling capacity and writes more data, a buffer overflow occurs. As a result, adjacent memory gets overwritten, leading to system issues.

There are two types of buffer overflow attacks:

• Stack overflow: This overwrites return addresses, allowing program flow redirection or arbitrary execution of code.
• Heap overflow: Dynamic memory structures get corrupted, leading to security breaches.

Buffer overflow can cause a variety of problems. System or application failure, data corruption that affects reliability and data integrity, and even illegal/unauthorized privilege escalation. With this privilege escalation, attackers may exploit the system by executing unauthorized code.

You can prevent buffer overload by:

• Validating buffer sizes and inputs.
• Using functions like strncpy instead of strcpy that can safely handle buffer size.
• Coding in programming languages with built-in protections like Java, C#, and Python.
• Using modern compilers with features like address space layout randomization and stack canaries.

Addressing vulnerabilities is an ongoing practice

When cybercriminals recognize a vulnerability in the system, they aim to exploit it. In most cases, software-related vulnerabilities can be fixed by installing a security patch issued by the vendor. Alternatively, open-source communities also provide patches to address these vulnerabilities.

In some cases of Zero-Day exploit, you may be exposed to higher risk but can maintain strong levels of security by encrypting sensitive data assets and using strong Identity and Access Management systems to control network access.