Contact Us Today 01642 716680


Definition: A vulnerability in cyber security refers to a flaw, loophole, or weakness in a software system or network that can be exploited by a threat actor to gain unauthorised access or perform unauthorised actions within a system.

Vulnerabilities are key focal points in cyber security because they represent potential entry points for attackers to infiltrate systems, compromise data, and cause damage. They may exist due to a variety of reasons, such as coding errors, incorrect system configurations, or software that is out of date. Identifying and addressing vulnerabilities is critical in protecting information systems and assets from cyber threats. This is often accomplished through practices such as vulnerability assessments, regular software updates, and following secure coding standards.

The timely remediation or mitigation of vulnerabilities is essential for maintaining strong security postures. Organisations commonly depend on patches provided by software vendors or employ protective measures until a vulnerability can be fully remedied.

Key Characteristics:

  • Inherent Weakness: A vulnerability is an inherent defect or weakness within software or hardware.
  • Potential for Exploitation: Vulnerabilities may be exploited to cause harm or unauthorised actions, such as data leakage, denial of service, or system takeover.
  • Requires Addressing: Effective cyber security practices involve identifying and resolving vulnerabilities promptly.
  • Diverse in Nature: Vulnerabilities can range from simple configuration errors to complex software bugs.


  • Real-World Example: The Heartbleed bug discovered in 2014 was a severe vulnerability in the OpenSSL cryptographic software library that allowed attackers to read the memory of systems protected by the vulnerable versions of OpenSSL.
  • Hypothetical Scenario: A software developer team finds that their web application inadvertently exposes API keys due to an oversight in access controls, creating a vulnerability that could lead to unauthorized access to their back-end services.

Related Terms:

  • Exploit: A technique that takes advantage of a vulnerability to gain unauthorised access or effect other undesirable outcomes.
  • Patch: A software update intended to correct or improve a program, often to fix a vulnerability.
  • Zero Day Vulnerability: A security vulnerability that is exploited before the developer is aware of its existence.

What is the OWASP Top 10: Download our flash cards to find out.

Inside you will find a description of the most common web vulnerabilities.

Contact us

Get a free, no obligation quote from one of our expert staff.