2.1 Vulnerability types
📘CompTIA Security+ SY0-701
Hardware vulnerabilities are weaknesses that exist in the physical components of a computer system or network device — such as routers, switches, servers, laptops, IoT devices, and printers.
These weaknesses can allow attackers to gain unauthorized access, cause system failure, or steal sensitive data.
The main types of hardware-related vulnerabilities that the Security+ exam expects you to know are:
- Firmware vulnerabilities
- End-of-life (EOL) vulnerabilities
- Legacy system vulnerabilities
Let’s understand each in detail.
🧩 1. Firmware Vulnerabilities
What is Firmware?
Firmware is software that’s built into hardware. It controls how the hardware operates.
For example, your computer’s BIOS/UEFI, your router’s operating system, or a network printer’s control system are all firmware.
Firmware is stored on a chip inside the hardware and allows the device to start up and perform its functions.
Why Firmware Is Vulnerable
- Firmware is often overlooked during updates or patching. Many administrators focus on operating system or application updates but ignore firmware.
- Firmware can be manipulated by attackers to gain persistent access, because it runs before the operating system.
- If attackers infect firmware, their malicious code remains even after the operating system is reinstalled or the hard drive is replaced.
Common Firmware Vulnerabilities
- Unpatched firmware – Old versions may have known security flaws.
- Weak update process – Some devices don’t verify update authenticity, allowing attackers to install fake firmware.
- Hardcoded credentials – Some firmware has default usernames/passwords that cannot be changed.
- Insecure interfaces – Management ports (e.g., web interfaces, SSH, telnet) can be exposed and unprotected.
- Supply chain tampering – Attackers may compromise firmware before the hardware even reaches the user.
How to Secure Firmware
- Regularly check for firmware updates from trusted vendors.
- Use digitally signed firmware to ensure authenticity.
- Disable unused management interfaces.
- Restrict physical and network access to firmware management tools.
- Enable Secure Boot (in modern systems) to ensure only trusted firmware loads during startup.
- Use hardware security modules (HSMs) or TPMs (Trusted Platform Modules) for secure firmware integrity checks.
🕒 2. End-of-Life (EOL) Vulnerabilities
What Is End-of-Life Hardware?
End-of-Life (EOL) means the manufacturer has stopped supporting that hardware device.
This includes no more updates, security patches, or customer support.
Examples include old network switches, older firewalls, or outdated printers that vendors no longer maintain.
Why EOL Devices Are Vulnerable
- No more security updates: If a vulnerability is discovered, it will never be patched.
- Incompatible with new software: Modern operating systems or management tools may not support it.
- Increased exposure: Attackers know EOL devices are not patched, making them easy targets.
- No vendor assistance: If the device fails or is compromised, the manufacturer can’t help fix it.
Risks in an IT Environment
- Attackers can exploit known vulnerabilities that remain unpatched.
- EOL devices might not support modern security features, like encryption or authentication protocols.
- They can weaken the entire network, even if other devices are secure.
- EOL equipment may fail unpredictably, causing downtime or data loss.
How to Handle EOL Devices
- Replace EOL hardware as soon as possible.
- If replacement is not immediate, isolate it on the network or use network segmentation.
- Restrict access only to trusted devices.
- Monitor for unusual activity.
- Keep a hardware lifecycle plan to avoid future EOL exposure.
🧮 3. Legacy System Vulnerabilities
What Are Legacy Systems?
Legacy systems are old hardware or software still in use because they perform important functions or are expensive to replace.
They may still work but are no longer supported or updated by the vendor.
Why Legacy Systems Are Vulnerable
- They lack modern security controls (like encryption, multifactor authentication, or modern firewalls).
- No patches or updates are provided.
- Incompatible with new security tools or standards.
- Weak default configurations remain unchanged because updating them could break business functions.
Security Risks
- Attackers can exploit old, well-documented vulnerabilities.
- Malware may spread easily because legacy systems can’t run new antivirus software.
- They can act as an entry point for attacks into the wider network.
- Often, administrators can’t apply patches because it may break compatibility with old applications.
How to Secure Legacy Systems
- Segment legacy systems from the rest of the network using VLANs or firewalls.
- Use application whitelisting to limit what runs on them.
- Implement strict access controls – only essential users should access legacy systems.
- Use virtualization – sometimes old systems can be run in a virtual machine with added protection layers.
- Plan a migration strategy – replace legacy systems gradually with modern, supported ones.
🧠 Summary Table
| Vulnerability Type | Description | Risks | Security Best Practices |
|---|---|---|---|
| Firmware | Software inside hardware devices controlling their functions | Persistent malware, rootkits, supply chain tampering | Update regularly, use signed firmware, enable Secure Boot |
| End-of-Life (EOL) | Device no longer supported by the manufacturer | No patches, exposed vulnerabilities, compliance risks | Replace or isolate, restrict access, monitor activity |
| Legacy Systems | Older systems still in use but unsupported | Outdated security, easy exploitation, weak encryption | Segment network, limit access, plan migration, virtualize |
💡 Key Takeaways for the Security+ Exam
- Firmware vulnerabilities happen due to outdated, tampered, or insecurely updated firmware.
- EOL vulnerabilities exist because the vendor stops support, leaving systems unpatched.
- Legacy vulnerabilities arise from old systems that still operate but can’t meet current security standards.
- All three types increase attack surfaces and can be exploited if not properly isolated, monitored, or replaced.
- The best protection is regular updates, network segmentation, access control, and planned hardware lifecycle management.
