Guides tagged “security”
Step-by-step MdmHost guides about security, sorted A-Z.
248 guides · page 11 of 13
Set up SSH key authentication on a Linux VPS
Generate an SSH key pair, copy the public key to your Linux VPS and log in without a password, then turn off password logins safely.
Set up SSH keys
Create an SSH key pair, add it to your Linux VPS from macOS, Linux or Windows, and optionally switch off password logins safely.
Set up the Proxmox VE firewall for the host and VMs
Enable the built-in Proxmox firewall safely: allow the web UI and SSH first, then add datacenter, node and per-VM rules, security groups and IP sets.
Softaculous auto-upgrades: keep apps, plugins and themes updated
Configure Softaculous automatic upgrades for WordPress core, plugins and themes, take a backup before each update, upgrade manually and handle failed upgrades.
SSH access in cPanel: generate, import and authorise SSH keys
Connect to your cPanel hosting over SSH with keys: generate or import a key in cPanel SSH Access, authorise it, and connect from Windows, macOS or Linux.
SSH Hardening: Auditing and Limiting Shell Access for Service Accounts
Audit every Linux account that has a login shell, move service accounts to nologin, and restrict SSH with AllowGroups and Match blocks so only people who need a session get one.
SSH Hardening: Auditing and Restricting Authorized Keys for Critical Services
Find every authorized_keys file on your Linux VPS, validate each key, and apply strict per-key restrictions so only the access you intend is possible.
SSH Hardening: Enforcing Key Rotation Policies for Automated Security
SSH key rotation replaces long-lived credentials before they become a permanent backdoor. This guide covers expiry dates in authorized_keys, a rotation script and auditing.
SSH Hardening: Mitigating Man-in-the-Middle Attacks with Host Key Verification
SSH host key verification makes your client confirm the server's identity before you send credentials. This guide shows how to read fingerprints, verify them out of band, pin them in known_hosts and rotate host keys without locking yourself out.
SSH tunnels: local, remote and dynamic (SOCKS) port forwarding
Use SSH port forwarding to reach a private database, expose a local service temporarily, or browse through your server with a SOCKS proxy.
SSL, TLS and HTTPS explained: how website encryption works
What SSL/TLS certificates are, how the HTTPS handshake protects visitors, the types of certificates (DV, OV, EV, wildcard), how validation works and why every site needs it.
Stop brute force and floods with Cloudflare rate limiting rules
Create Cloudflare rate limiting rules that slow down login brute force, search and checkout abuse, and small HTTP floods, with sensible thresholds and testing tips.
Stop comment and form spam on WordPress
Reduce WordPress comment and contact form spam: discussion settings, moderation rules, anti-spam plugins, honeypots and CAPTCHA, and cleaning up existing spam.
Stop Docker from bypassing your UFW firewall
Docker-published ports skip UFW rules and stay open to the internet. Learn why it happens, how to bind ports to 127.0.0.1, how to filter with the DOCKER-USER chain and how to test from outside.
Stop fraudulent orders in WHMCS with fraud protection settings
Enable MaxMind or FraudLabs Pro in WHMCS, set risk score thresholds, require order approval, use CAPTCHA and order rules to block card testing and fake signups.
Stop hotlinking and password sharing: Hotlink and Leech Protection in cPanel
Stop other websites from embedding your images and stealing bandwidth with cPanel Hotlink Protection, and block shared passwords with Leech Protection.
Stop image hotlinking with DirectAdmin Hotlink Protection
Enable Hotlink Protection in DirectAdmin to stop other sites embedding your images and files, allow your own domains and search engines, and redirect blocked requests.
Stop outgoing spam from your mail server with rate limits
How hacked mailboxes and scripts send spam from servers, how to detect it in logs and queues, and how to limit outgoing mail per user and per domain on Postfix, Exim and cPanel.
Test firewall changes safely with an automatic rollback
Schedule an automatic undo before you change firewall rules. If a mistake blocks SSH, the old rules come back by themselves a few minutes later.
The 3-2-1 backup rule for websites: a practical backup strategy
How to apply the 3-2-1 backup rule to a website or hosting business: three copies, two media, one offsite, plus retention, testing restores and ransomware-resistant copies.
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