Cybersecurity: Defensive (SOC)

Sefism.

A to Z

Glossary

Every concept in this sheet, plus the smaller terms it uses. Select a concept to open its card.

A
Authentication and authorisation
Authentication proves who you are; authorisation decides what you are allowed to do once the system knows who you are.
Authorised testing and the law
In most countries, accessing or testing a computer system without the owner's permission is a crime, whatever your intention.
C
CIA triad
The three properties security protects: confidentiality (only the right people can read it), integrity (nobody can change it unnoticed) and availability (it works when needed).
CVSS
An open standard from FIRST that scores a vulnerability from 0 to 10 using factors such as how it is reached, the privileges needed and its impact.
D
Defence in depth
Using several independent layers of control, such as MFA, patching, network rules, monitoring and backups, so one failure does not mean a breach.
H
Hashing
A one-way function that turns data into a fixed-size fingerprint.
I
Intentionally vulnerable apps
Applications built with documented weaknesses so people can learn to find, fix and detect them legally, such as OWASP Juice Shop.
Isolated lab network
A hypervisor network mode, such as host-only or internal, that lets lab machines talk to each other but not to your home network or the internet.
L
Lab notes
One page per exercise recording date, goal, steps, observations, meaning, and how the issue is prevented or detected, with captioned screenshots.
Least privilege
Giving each person, service and process only the access it needs to do its job, and only for as long as it needs it.
M
Multi-factor authentication
Requiring two or more kinds of proof to sign in: something you know, something you have or something you are.
N
Networking basics for security
IP addresses and subnets, TCP and UDP, ports, DNS, HTTP and HTTPS, and what firewalls and proxies do: the path every connection takes.
P
Practice platform rules
Each platform's rules on what you may test (only the machines it gives you), what is banned (attacking the platform or other users) and what you may publish.
R
Risk, threat and vulnerability
A vulnerability is a weakness, a threat is someone or something that could exploit it, and risk combines how likely that is with how bad the outcome would be.
Running targets in containers
Starting practice apps and tools as containers, with ports published only on 127.0.0.1 so only your own machine can reach them.
S
Scripting for security
Small scripts that read logs, filter and count events, or query a system, written in Python, Bash or PowerShell.
Snapshot
A saved state of a virtual machine that you can return to in seconds.
Symmetric and asymmetric encryption
Symmetric encryption uses one shared key and is fast.
T
TLS
The protocol that encrypts and authenticates connections such as HTTPS.
V
Virtual machine
A complete computer running as software inside your own, managed by a hypervisor such as VirtualBox, VMware Workstation or Hyper-V.
09 · Glossary, A to Z9 / 9