A vulnerability represents a weak point though which the security of a computer can be breached. A vulnerability is a programming error in an application that can be exploited to gain access to the computer with that program installed.

Generally, this programming error refers to operations that cause the application to malfunction. This bug can be reproduced artificially by a malicious user in order to gain access to computers without the user's permission. Sometimes, this can be done by simply opening a specially crafted document.

This would allow a malicious user to carry out a wide range of actions on the vulnerable computer, for example, running or deleting files, inserting viruses, accessing information, etc.

Although the most commonly known vulnerabilities are those affecting operating systems, Internet browsers and mail programs, any program can have vulnerabilities: word processing applications, databases, sound file players, etc.

A vulnerability does not pose an immediate threat to computers. However, it is a potential entry point for other threats, such as viruses, worms and Trojans, which can have destructive effects.

For this reason, it is highly advisable to keep informed about the vulnerabilities discovered in the programs you have installed and apply the latest security patches released by manufacturers of these applications, which are usually available on their websites.

Some examples of worms that exploit vulnerabilities in order to carry out their actions are: Blaster, Bugbear.B, Klez.I and Nachi.A.