week 10

K1.10 The potential vulnerabilities in critical systems:

A vulnerability is a weakness in a system that can be exploited by a threat actor (such as a hacker) or caused by human error, poor design, or lack of security controls.

In critical systems—such as servers, network infrastructure, and secure workstations—vulnerabilities can lead to data loss, downtime, and serious security breaches.

Below are some of the key vulnerabilities found in organisations.

---

Unauthorised Access to Network Infrastructure

What it is:

When people (inside or outside the organisation) gain unauthorised access to core components like switches, routers, firewalls, or servers.

Why it’s a risk:

• Allows attackers to monitor, manipulate, or redirect network traffic

• May expose internal systems to external attacks

Example:

• Weak router admin password is guessed, giving full control to an attacker

Mitigation:

• Use strong passwords

• Apply network segmentation

• Limit access using Access Control Lists (ACLs)

Unauthorised Physical Access to Network Ports

What it is:

When someone physically connects a device (e.g. laptop or USB stick) to network ports without permission.

Why it’s a risk:

• Attackers could connect to the network bypassing firewalls

• Could be used to install malware or spyware

Example:

• An unauthorised visitor plugs into a network socket in a meeting room

Mitigation:

• Lock unused ports

• Use port security settings on switches

• Implement visitor access policies

Single Point of Failure

What it is:

A single component (like a server or router) that, if it fails, causes the entire system or service to stop working.

Why it’s a risk:

• A single failure can lead to major downtime

• Makes the organisation less resilient

Example:

• Only one database server handles all staff records – if it crashes, the service goes down

Mitigation:

• Use redundancy (backup systems)

• Set up load balancing and failover systems

System Failure

What it is:

A system crash or malfunction caused by hardware issues, software bugs, or poor maintenance.

Why it’s a risk:

• Could result in data loss, service interruption, or security exposure

Example:

• An old, unpatched server operating system crashes and cannot reboot

Mitigation:

• Keep systems updated and patched

• Perform regular health checks and monitoring

• Maintain service-level agreements (SLAs) for critical hardware

Open Port Access

What it is:

When input/output ports on devices (e.g. USB, CD drives, or wireless) are unrestricted, allowing for unauthorised data transfer or malware infection.

Why it’s a risk:

• Can be used to exfiltrate data, introduce viruses, or bypass network restrictions

Includes:

Mitigation:

• Disable unused ports

• Use endpoint security tools

• Apply device control policies

• Ensure Wi-Fi networks use strong encryption (e.g. WPA3)

Secure the Network – Spot the Vulnerability

Scenario:
You’ve been asked to assess the computer network at a local business. During your visit, you notice:

- A USB stick left in a PC
- An unlocked server cabinet
- Only one file server being used
- Guest Wi-Fi with no password

Task:
1. Identify the vulnerabilities
2. Explain the risks for each
3. Recommend one solution per vulnerability

Extension:
Create a network security checklist that an IT team could use during a weekly inspection.

Last Updated
2025-07-14 08:33:57